HEADSC 1g0w
COMMNT S2C correlation file created: Sat Dec 27 10:20:52 EST 2003
COMMNT
COMMNT If you use this database, please cite:
COMMNT
COMMNT Guoli Wang, Jonathan W. Arthur, and Roland L. Dunbrack, Jr.
COMMNT "S2C: A database correlating sequence and atomic
COMMNT   coordinate numbering in the Protein Data Bank"
COMMNT   www.fccc.edu/research/labs/dubrack/s2c
COMMNT   Copyright (c) February 2000, April 2002.
COMMNT
COMMNT SEQCRD columns are as follows:
COMMNT
COMMNT Column Positions Item
COMMNT      1       0-6 Record identifier
COMMNT      2         8 Chain
COMMNT      3        10 One letter residue code
COMMNT      4     12-14 SEQRES three letter residue code
COMMNT      5     16-18 ATOM three letter residue code
COMMNT      6     20-24 SEQRES residue number
COMMNT      7     26-31 ATOM residue number
COMMNT      8        33 PDB secondary structure
COMMNT      9        35 STRIDE secondary structure
COMMNT     10     37-43 Error flags
COMMNT
COMMNT Secondary structrue annotation:
COMMNT     H: Helix      E: Strand     T: Turn
COMMNT     B: Bridge     G: 310Helix   C: Coil
COMMNT
SEQCRD A P PRO PRO     1      2 C C 4      
SEQCRD A F PHE PHE     2      3 C C 4      
SEQCRD A S SER SER     3      4 C C 4      
SEQCRD A N ASN ASN     4      5 H C 45     
SEQCRD A S SER SER     5      6 H H 4      
SEQCRD A H HIS HIS     6      7 H H 4      
SEQCRD A N ASN ASN     7      8 H H 4      
SEQCRD A T THR THR     8      9 H H 4      
SEQCRD A L LEU LEU     9     10 H H 4      
SEQCRD A K LYS LYS    10     11 H H 4      
SEQCRD A L LEU LEU    11     12 H H 4      
SEQCRD A R ARG ARG    12     13 C T 45     
SEQCRD A F PHE PHE    13     14 C T 45     
SEQCRD A P PRO PRO    14     15 H T 45     
SEQCRD A A ALA ALA    15     16 H G 45     
SEQCRD A E GLU GLU    16     17 H G 45     
SEQCRD A D ASP ASP    17     18 H G 45     
SEQCRD A E GLU GLU    18     19 H C 45     
SEQCRD A F PHE PHE    19     20 H C 45     
SEQCRD A P PRO PRO    20     21 C C 4      
SEQCRD A D ASP ASP    21     22 C C 4      
SEQCRD A L LEU LEU    22     23 C T 45     
SEQCRD A S SER SER    23     24 C T 45     
SEQCRD A G GLY GLY    24     25 C T 45     
SEQCRD A H HIS HIS    25     26 C T 45     
SEQCRD A N ASN ASN    26     27 C C 4      
SEQCRD A N ASN ASN    27     28 H B 45     
SEQCRD A H HIS HIS    28     29 H H 4      
SEQCRD A M MET MET    29     30 H H 4      
SEQCRD A A ALA ALA    30     31 H H 4      
SEQCRD A K LYS LYS    31     32 H H 4      
SEQCRD A V VAL VAL    32     33 H H 4      
SEQCRD A L LEU LEU    33     34 H C 45     
SEQCRD A T THR THR    34     35 H C 45     
SEQCRD A P PRO PRO    35     36 H H 4      
SEQCRD A E GLU GLU    36     37 H H 4      
SEQCRD A L LEU LEU    37     38 H H 4      
SEQCRD A Y TYR TYR    38     39 H H 4      
SEQCRD A A ALA ALA    39     40 H H 4      
SEQCRD A E GLU GLU    40     41 H H 4      
SEQCRD A L LEU LEU    41     42 H H 4      
SEQCRD A R ARG ARG    42     43 H H 4      
SEQCRD A A ALA ALA    43     44 C C 4      
SEQCRD A K LYS LYS    44     45 C C 4      
SEQCRD A S SER SER    45     46 C B 45     
SEQCRD A T THR THR    46     47 C T 45     
SEQCRD A P PRO PRO    47     48 C T 45     
SEQCRD A S SER SER    48     49 C T 45     
SEQCRD A G GLY GLY    49     50 C T 45     
SEQCRD A F PHE PHE    50     51 C C 4      
SEQCRD A T THR THR    51     52 H B 45     
SEQCRD A V VAL VAL    52     53 H H 4      
SEQCRD A D ASP ASP    53     54 H H 4      
SEQCRD A D ASP ASP    54     55 H H 4      
SEQCRD A V VAL VAL    55     56 H H 4      
SEQCRD A I ILE ILE    56     57 H H 4      
SEQCRD A Q GLN GLN    57     58 H H 4      
SEQCRD A T THR THR    58     59 H H 4      
SEQCRD A G GLY GLY    59     60 H H 4      
SEQCRD A V VAL VAL    60     61 H H 4      
SEQCRD A D ASP ASP    61     62 H H 4      
SEQCRD A N ASN ASN    62     63 H C 45     
SEQCRD A P PRO PRO    63     64 C C 4      
SEQCRD A G GLY GLY    64     65 C C 4      
SEQCRD A H HIS HIS    65     66 C B 45     
SEQCRD A P PRO PRO    66     67 C T 45     
SEQCRD A Y TYR TYR    67     68 C T 45     
SEQCRD A I ILE ILE    68     69 C B 45     
SEQCRD A M MET MET    69     70 C C 4      
SEQCRD A T THR THR    70     71 C B 45     
SEQCRD A V VAL VAL    71     72 C C 4      
SEQCRD A G GLY GLY    72     73 C C 4      
SEQCRD A C CYS CYS    73     74 C C 4      
SEQCRD A V VAL VAL    74     75 C C 4      
SEQCRD A A ALA ALA    75     76 C C 4      
SEQCRD A G GLY GLY    76     77 C C 4      
SEQCRD A D ASP ASP    77     78 C C 4      
SEQCRD A E GLU GLU    78     79 C C 4      
SEQCRD A E GLU GLU    79     80 H H 4      
SEQCRD A S SER SER    80     81 H H 4      
SEQCRD A Y TYR TYR    81     82 H H 4      
SEQCRD A D ASP ASP    82     83 H H 4      
SEQCRD A V VAL VAL    83     84 H H 4      
SEQCRD A F PHE PHE    84     85 H H 4      
SEQCRD A K LYS LYS    85     86 H H 4      
SEQCRD A E GLU GLU    86     87 H H 4      
SEQCRD A L LEU LEU    87     88 H H 4      
SEQCRD A F PHE PHE    88     89 H H 4      
SEQCRD A D ASP ASP    89     90 H H 4      
SEQCRD A P PRO PRO    90     91 H H 4      
SEQCRD A I ILE ILE    91     92 H H 4      
SEQCRD A I ILE ILE    92     93 H H 4      
SEQCRD A E GLU GLU    93     94 H H 4      
SEQCRD A D ASP ASP    94     95 H H 4      
SEQCRD A R ARG ARG    95     96 H H 4      
SEQCRD A H HIS HIS    96     97 H H 4      
SEQCRD A G GLY GLY    97     98 C T 45     
SEQCRD A G GLY GLY    98     99 C T 45     
SEQCRD A Y TYR TYR    99    100 C T 45     
SEQCRD A K LYS LYS   100    101 C T 45     
SEQCRD A P PRO PRO   101    102 C T 45     
SEQCRD A T THR THR   102    103 C T 45     
SEQCRD A D ASP ASP   103    104 C T 45     
SEQCRD A E GLU GLU   104    105 C C 4      
SEQCRD A H HIS HIS   105    106 C C 4      
SEQCRD A K LYS LYS   106    107 C C 4      
SEQCRD A T THR THR   107    108 C C 4      
SEQCRD A D ASP ASP   108    109 C C 4      
SEQCRD A L LEU LEU   109    110 C C 4      
SEQCRD A N ASN ASN   110    111 H C 45     
SEQCRD A P PRO PRO   111    112 H G 45     
SEQCRD A D ASP ASP   112    113 H G 45     
SEQCRD A N ASN ASN   113    114 H G 45     
SEQCRD A L LEU LEU   114    115 H C 45     
SEQCRD A Q GLN GLN   115    116 C C 4      
SEQCRD A G GLY GLY   116    117 C C 4      
SEQCRD A G GLY GLY   117    118 C T 45     
SEQCRD A D ASP ASP   118    119 C T 45     
SEQCRD A D ASP ASP   119    120 C T 45     
SEQCRD A L LEU LEU   120    121 C T 45     
SEQCRD A D ASP ASP   121    122 C T 45     
SEQCRD A P PRO PRO   122    123 C T 45     
SEQCRD A N ASN ASN   123    124 C T 45     
SEQCRD A Y TYR TYR   124    125 C T 45     
SEQCRD A V VAL VAL   125    126 E E 4      
SEQCRD A L LEU LEU   126    127 E E 4      
SEQCRD A S SER SER   127    128 E E 4      
SEQCRD A S SER SER   128    129 E E 4      
SEQCRD A R ARG ARG   129    130 E E 4      
SEQCRD A V VAL VAL   130    131 E E 4      
SEQCRD A R ARG ARG   131    132 E E 4      
SEQCRD A T THR THR   132    133 E E 4      
SEQCRD A G GLY GLY   133    134 E E 4      
SEQCRD A R ARG ARG   134    135 E E 4      
SEQCRD A S SER SER   135    136 C C 4      
SEQCRD A I ILE ILE   136    137 C B 45     
SEQCRD A R ARG ARG   137    138 C T 45     
SEQCRD A G GLY GLY   138    139 C T 45     
SEQCRD A F PHE PHE   139    140 C T 45     
SEQCRD A C CYS CYS   140    141 C C 4      
SEQCRD A L LEU LEU   141    142 C T 45     
SEQCRD A P PRO PRO   142    143 C T 45     
SEQCRD A P PRO PRO   143    144 C T 45     
SEQCRD A H HIS HIS   144    145 C T 45     
SEQCRD A C CYS CYS   145    146 C T 45     
SEQCRD A S SER SER   146    147 H C 45     
SEQCRD A R ARG ARG   147    148 H H 4      
SEQCRD A G GLY GLY   148    149 H H 4      
SEQCRD A E GLU GLU   149    150 H H 4      
SEQCRD A R ARG ARG   150    151 H H 4      
SEQCRD A R ARG ARG   151    152 H H 4      
SEQCRD A A ALA ALA   152    153 H H 4      
SEQCRD A I ILE ILE   153    154 H H 4      
SEQCRD A E GLU GLU   154    155 H H 4      
SEQCRD A K LYS LYS   155    156 H H 4      
SEQCRD A L LEU LEU   156    157 H H 4      
SEQCRD A A ALA ALA   157    158 H H 4      
SEQCRD A V VAL VAL   158    159 H H 4      
SEQCRD A E GLU GLU   159    160 H H 4      
SEQCRD A A ALA ALA   160    161 H H 4      
SEQCRD A L LEU LEU   161    162 H H 4      
SEQCRD A S SER SER   162    163 H H 4      
SEQCRD A S SER SER   163    164 H C 45     
SEQCRD A L LEU LEU   164    165 H C 45     
SEQCRD A D ASP ASP   165    166 H C 45     
SEQCRD A G GLY GLY   166    167 H G 45     
SEQCRD A D ASP ASP   167    168 H G 45     
SEQCRD A L LEU LEU   168    169 H G 45     
SEQCRD A A ALA ALA   169    170 C C 4      
SEQCRD A G GLY GLY   170    171 E E 4      
SEQCRD A R ARG ARG   171    172 E E 4      
SEQCRD A Y TYR TYR   172    173 E E 4      
SEQCRD A Y TYR TYR   173    174 E E 4      
SEQCRD A A ALA ALA   174    175 E E 4      
SEQCRD A L LEU LEU   175    176 C G 45     
SEQCRD A K LYS LYS   176    177 H G 45     
SEQCRD A S SER SER   177    178 H G 45     
SEQCRD A M MET MET   178    179 H C 45     
SEQCRD A T THR THR   179    180 H C 45     
SEQCRD A E GLU GLU   180    181 H H 4      
SEQCRD A A ALA ALA   181    182 H H 4      
SEQCRD A E GLU GLU   182    183 H H 4      
SEQCRD A Q GLN GLN   183    184 H H 4      
SEQCRD A Q GLN GLN   184    185 H H 4      
SEQCRD A Q GLN GLN   185    186 H H 4      
SEQCRD A L LEU LEU   186    187 H H 4      
SEQCRD A I ILE ILE   187    188 H H 4      
SEQCRD A D ASP ASP   188    189 H H 4      
SEQCRD A D ASP ASP   189    190 H H 4      
SEQCRD A H HIS HIS   190    191 H C 45     
SEQCRD A F PHE PHE   191    192 C C 4      
SEQCRD A L LEU LEU   192    193 C C 4      
SEQCRD A F PHE PHE   193    194 C C 4      
SEQCRD A D ASP ASP   194    195 C C 4      
SEQCRD A K LYS LYS   195    196 C C 4      
SEQCRD A P PRO PRO   196    197 C C 4      
SEQCRD A V VAL VAL   197    198 C C 4      
SEQCRD A S SER SER   198    199 H C 45     
SEQCRD A P PRO PRO   199    200 H H 4      
SEQCRD A L LEU LEU   200    201 H H 4      
SEQCRD A L LEU LEU   201    202 H H 4      
SEQCRD A L LEU LEU   202    203 H H 4      
SEQCRD A A ALA ALA   203    204 H H 4      
SEQCRD A S SER SER   204    205 C C 4      
SEQCRD A G GLY GLY   205    206 C T 45     
SEQCRD A M MET MET   206    207 C T 45     
SEQCRD A A ALA ALA   207    208 C T 45     
SEQCRD A R ARG ARG   208    209 C T 45     
SEQCRD A D ASP ASP   209    210 C T 45     
SEQCRD A W TRP TRP   210    211 C T 45     
SEQCRD A P PRO PRO   211    212 C T 45     
SEQCRD A D ASP ASP   212    213 C T 45     
SEQCRD A A ALA ALA   213    214 C T 45     
SEQCRD A R ARG ARG   214    215 C T 45     
SEQCRD A G GLY GLY   215    216 E E 4      
SEQCRD A I ILE ILE   216    217 E E 4      
SEQCRD A W TRP TRP   217    218 E E 4      
SEQCRD A H HIS HIS   218    219 E E 4      
SEQCRD A N ASN ASN   219    220 E E 4      
SEQCRD A D ASP ASP   220    221 C T 45     
SEQCRD A N ASN ASN   221    222 C T 45     
SEQCRD A K LYS LYS   222    223 C T 45     
SEQCRD A T THR THR   223    224 C C 4      
SEQCRD A F PHE PHE   224    225 E E 4      
SEQCRD A L LEU LEU   225    226 E E 4      
SEQCRD A V VAL VAL   226    227 E E 4      
SEQCRD A W TRP TRP   227    228 E E 4      
SEQCRD A I ILE ILE   228    229 E E 4      
SEQCRD A N ASN ASN   229    230 C T 45     
SEQCRD A E GLU GLU   230    231 C T 45     
SEQCRD A E GLU GLU   231    232 C T 45     
SEQCRD A D ASP ASP   232    233 C T 45     
SEQCRD A H HIS HIS   233    234 C T 45     
SEQCRD A L LEU LEU   234    235 E E 4      
SEQCRD A R ARG ARG   235    236 E E 4      
SEQCRD A V VAL VAL   236    237 E E 4      
SEQCRD A I ILE ILE   237    238 E E 4      
SEQCRD A S SER SER   238    239 E E 4      
SEQCRD A M MET MET   239    240 E E 4      
SEQCRD A Q GLN GLN   240    241 E E 4      
SEQCRD A K LYS LYS   241    242 E E 4      
SEQCRD A G GLY GLY   242    243 C C 4      
SEQCRD A G GLY GLY   243    244 C T 45     
SEQCRD A N ASN ASN   244    245 H T 45     
SEQCRD A M MET MET   245    246 H H 4      
SEQCRD A K LYS LYS   246    247 H H 4      
SEQCRD A E GLU GLU   247    248 H H 4      
SEQCRD A V VAL VAL   248    249 H H 4      
SEQCRD A F PHE PHE   249    250 H H 4      
SEQCRD A T THR THR   250    251 H H 4      
SEQCRD A R ARG ARG   251    252 H H 4      
SEQCRD A F PHE PHE   252    253 H H 4      
SEQCRD A C CYS CYS   253    254 H H 4      
SEQCRD A N ASN ASN   254    255 H H 4      
SEQCRD A G GLY GLY   255    256 H H 4      
SEQCRD A L LEU LEU   256    257 H H 4      
SEQCRD A T THR THR   257    258 H H 4      
SEQCRD A Q GLN GLN   258    259 H H 4      
SEQCRD A I ILE ILE   259    260 H H 4      
SEQCRD A E GLU GLU   260    261 H H 4      
SEQCRD A T THR THR   261    262 H H 4      
SEQCRD A L LEU LEU   262    263 H H 4      
SEQCRD A F PHE PHE   263    264 H H 4      
SEQCRD A K LYS LYS   264    265 H H 4      
SEQCRD A S SER SER   265    266 H H 4      
SEQCRD A K LYS LYS   266    267 H H 4      
SEQCRD A N ASN ASN   267    268 C C 4      
SEQCRD A Y TYR TYR   268    269 C C 4      
SEQCRD A E GLU GLU   269    270 C C 4      
SEQCRD A F PHE PHE   270    271 C B 45     
SEQCRD A M MET MET   271    272 C C 4      
SEQCRD A W TRP TRP   272    273 E E 4      
SEQCRD A N ASN ASN   273    274 E E 4      
SEQCRD A P PRO PRO   274    275 C T 45     
SEQCRD A H HIS HIS   275    276 C T 45     
SEQCRD A L LEU LEU   276    277 C T 45     
SEQCRD A G GLY GLY   277    278 E E 4      
SEQCRD A Y TYR TYR   278    279 E E 4      
SEQCRD A I ILE ILE   279    280 C T 45     
SEQCRD A L LEU LEU   280    281 C C 4      
SEQCRD A T THR THR   281    282 C C 4      
SEQCRD A C CYS CYS   282    283 H T 45     
SEQCRD A P PRO PRO   283    284 H T 45     
SEQCRD A S SER SER   284    285 H T 45     
SEQCRD A N ASN ASN   285    286 H T 45     
SEQCRD A L LEU LEU   286    287 H T 45     
SEQCRD A G GLY GLY   287    288 C B 45     
SEQCRD A T THR THR   288    289 C T 45     
SEQCRD A G GLY GLY   289    290 C T 45     
SEQCRD A L LEU LEU   290    291 C E 45     
SEQCRD A R ARG ARG   291    292 E E 4      
SEQCRD A A ALA ALA   292    293 E E 4      
SEQCRD A G GLY GLY   293    294 E E 4      
SEQCRD A V VAL VAL   294    295 E E 4      
SEQCRD A H HIS HIS   295    296 E E 4      
SEQCRD A I ILE ILE   296    297 E E 4      
SEQCRD A K LYS LYS   297    298 E E 4      
SEQCRD A L LEU LEU   298    299 C T 45     
SEQCRD A P PRO PRO   299    300 C T 45     
SEQCRD A H HIS HIS   300    301 C T 45     
SEQCRD A L LEU LEU   301    302 C G 45     
SEQCRD A G GLY GLY   302    303 C G 45     
SEQCRD A K LYS LYS   303    304 C G 45     
SEQCRD A H HIS HIS   304    305 C C 4      
SEQCRD A E GLU GLU   305    306 C C 4      
SEQCRD A K LYS LYS   306    307 H H 4      
SEQCRD A F PHE PHE   307    308 H H 4      
SEQCRD A S SER SER   308    309 H H 4      
SEQCRD A E GLU GLU   309    310 H H 4      
SEQCRD A V VAL VAL   310    311 H H 4      
SEQCRD A L LEU LEU   311    312 H H 4      
SEQCRD A K LYS LYS   312    313 H H 4      
SEQCRD A R ARG ARG   313    314 H H 4      
SEQCRD A L LEU LEU   314    315 H H 4      
SEQCRD A R ARG ARG   315    316 H C 45     
SEQCRD A L LEU LEU   316    317 E E 4      
SEQCRD A Q GLN GLN   317    318 E E 4      
SEQCRD A K LYS LYS   318    319 E E 4      
SEQCRD A R ARG ARG   319    320 E E 4      
SEQCRD A G GLY GLY   320    321 C C 4      
SEQCRD A T THR ---   321      - - - 367    
SEQCRD A G GLY ---   322      - - - 367    
SEQCRD A G GLY ---   323      - - - 367    
SEQCRD A V VAL ---   324      - - - 367    
SEQCRD A D ASP ---   325      - - - 367    
SEQCRD A T THR ---   326      - - - 367    
SEQCRD A A ALA ---   327      - - - 367    
SEQCRD A A ALA ---   328      - - - 367    
SEQCRD A V VAL VAL   329    330 C T 45     
SEQCRD A G GLY GLY   330    331 C T 45     
SEQCRD A G GLY GLY   331    332 C T 45     
SEQCRD A V VAL VAL   332    333 E E 4      
SEQCRD A F PHE PHE   333    334 E E 4      
SEQCRD A D ASP ASP   334    335 E E 4      
SEQCRD A V VAL VAL   335    336 E E 4      
SEQCRD A S SER SER   336    337 E E 4      
SEQCRD A N ASN ASN   337    338 E E 4      
SEQCRD A A ALA ALA   338    339 C C 4      
SEQCRD A D ASP ASP   339    340 C C 4      
SEQCRD A R ARG ARG   340    341 C T 45     
SEQCRD A L LEU LEU   341    342 C T 45     
SEQCRD A G GLY GLY   342    343 C T 45     
SEQCRD A F PHE PHE   343    344 C T 45     
SEQCRD A S SER SER   344    345 H C 45     
SEQCRD A E GLU GLU   345    346 H H 4      
SEQCRD A V VAL VAL   346    347 H H 4      
SEQCRD A E GLU GLU   347    348 H H 4      
SEQCRD A L LEU LEU   348    349 H H 4      
SEQCRD A V VAL VAL   349    350 H H 4      
SEQCRD A Q GLN GLN   350    351 H H 4      
SEQCRD A M MET MET   351    352 H H 4      
SEQCRD A V VAL VAL   352    353 H H 4      
SEQCRD A V VAL VAL   353    354 H H 4      
SEQCRD A D ASP ASP   354    355 H H 4      
SEQCRD A G GLY GLY   355    356 H H 4      
SEQCRD A V VAL VAL   356    357 H H 4      
SEQCRD A K LYS LYS   357    358 H H 4      
SEQCRD A L LEU LEU   358    359 H H 4      
SEQCRD A L LEU LEU   359    360 H H 4      
SEQCRD A I ILE ILE   360    361 H H 4      
SEQCRD A E GLU GLU   361    362 H H 4      
SEQCRD A M MET MET   362    363 H H 4      
SEQCRD A E GLU GLU   363    364 H H 4      
SEQCRD A Q GLN GLN   364    365 H H 4      
SEQCRD A R ARG ARG   365    366 H H 4      
SEQCRD A L LEU LEU   366    367 H H 4      
SEQCRD A E GLU GLU   367    368 H H 4      
SEQCRD A Q GLN GLN   368    369 H H 4      
SEQCRD A G GLY GLY   369    370 H C 45     
SEQCRD A Q GLN GLN   370    371 C C 4      
SEQCRD A A ALA ALA   371    372 C C 4      
SEQCRD A I ILE ILE   372    373 C T 45     
SEQCRD A D ASP ASP   373    374 C T 45     
SEQCRD A D ASP ASP   374    375 C T 45     
SEQCRD A L LEU LEU   375    376 C T 45     
SEQCRD A M MET MET   376    377 C T 45     
SEQCRD A P PRO PRO   377    378 C C 4      
SEQCRD A A ALA ALA   378    379 C C 4      
SEQCRD A Q GLN GLN   379    380 C C 4      
SEQCRD A K LYS LYS   380    381 C C 4      
COMMNT
S2CERR 1      0 No standard amino acid code
S2CERR 2      0 SEQRES and ATOM residue names differ
S2CERR 3      8 No ATOM record
S2CERR 4    372 SEQRES and ATOM residue numbers differ
S2CERR 5    126 PDB and STRIDE secondary structures differ
S2CERR 6      8 PDB secondary structure is absent
S2CERR 7      8 STRIDE secondary structure is absent
COMMNT
COMMNT Crystallographic technical parameters:
PARAME    method     'X-RAY DIFFRACTION'
PARAME    resolution 2.30
PARAME    R-factor   0.197
PARAME    B-factor   39.0
COMMNT
COMMNT Reference database information:
DATABA    source:
COMMNT
DATABA    mutation: