3CI3:
reference: Structural characterization of a human-type corrinoid adenosyltransferase confirms that coenzyme B12 is synthesized through a four-coordinate intermediate., St Maurice M, Mera P, Park K, Brunold TC, Escalante-Semerena JC, Rayment I, Biochemistry. 2008 May 27;47(21):5755-66. Epub 2008 May 2. PMID: 18452306

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