PMID: 16154095 , Related PDB id: 1VLP

Authors:

Chappie JS, Canaves JM, Han GW, Rife CL, Xu Q, Stevens RC

Title:

The structure of a eukaryotic nicotinic acid phosphoribosyltransferase reveals structural heterogeneity among type II PRTases.

Journal:

Structure. 2005 Sep;13(9):1385-96.

Abstract:

Nicotinamide adenine dinucleotide (NAD) is an essential cofactor for cellular redox reactions and can act as an important substrate in numerous biological processes. As a result, nature has evolved multiple biosynthetic pathways to meet this high chemical demand. In Saccharomyces cerevisiae, the NAD salvage pathway relies on the activity of nicotinic acid phosphoribosyltransferase (NAPRTase), a member of the phosphoribosyltransferase (PRTase) superfamily. Here, we report the structure of a eukaryotic (yeast) NAPRTase at 1.75 A resolution (locus name: YOR209C, gene name: NPT1). The structure reveals a two-domain fold that resembles the architecture of quinolinic acid phosphoribosyltransferases (QAPRTases), but with completely different dispositions that provide evidence for structural heterogeneity among the Type II PRTases. The identification of a third domain in NAPRTases provides a structural basis and possible mechanism for the functional modulation of this family of enzymes by ATP.