1nb9
From Proteopedia
Crystal Structure of Riboflavin Kinase
Overview
Riboflavin kinase (RFK) is an essential enzyme catalyzing the phosphorylation of riboflavin (vitamin B(2)) to form FMN, an obligatory step in vitamin B(2) utilization and flavin cofactor synthesis. The structure of human RFK revealed a six-stranded antiparallel beta barrel core structurally similar to the riboflavin synthase/ferredoxin reductase FAD binding domain fold. The binding site of an intrinsically bound MgADP defines a novel nucleotide binding motif that encompasses a loop, a 3(10) helix, and a reverse turn followed by a short beta strand. This active site loop forms an arch with ATP and riboflavin binding at the opposite side and the phosphoryl transfer appears to occur through the hole underneath the arch. The invariant residues Asn36 and Glu86 are implicated in the catalysis.
About this Structure
1NB9 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of human riboflavin kinase reveals a beta barrel fold and a novel active site arch., Karthikeyan S, Zhou Q, Mseeh F, Grishin NV, Osterman AL, Zhang H, Structure. 2003 Mar;11(3):265-73. PMID:12623014 Page seeded by OCA on Sat May 3 02:19:38 2008
