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B6db references: 22767596

type Journal Article
authors Komori H, Nitta Y, Ueno H, Higuchi Y.
title Structural study reveals that Ser-354 determines substrate specificity on human histidine decarboxylase.
journal J Biol Chem.
Activity 4.1.1.22
Family 4.1.1.22.b
sel unselected
ui 22767596
year (2012)
volume 287
number 34
pages 29175-83
 
abstract Histamine is an important chemical mediator for a wide variety of physiological reactions. L-histidine decarboxylase (HDC) is the primary enzyme responsible for histamine synthesis and produces histamine from histidine in a one-step reaction. In this study, we determined the crystal structure of human HDC (hHDC) complexed with the inhibitor histidine methyl ester. This structure shows the detailed features of the pyridoxal-5'-phosphate inhibitor adduct (external aldimine) at the active site of HDC. Moreover, a comparison of the structures of hHDC and aromatic L-amino acid (L-DOPA) decarboxylase showed that Ser-354 was a key residue for substrate specificity. The S354G mutation at the active site enlarged the size of the hHDC substrate-binding pocket and resulted in a decreased affinity for histidine, but an acquired ability to bind and act on L-DOPA as a substrate. These data provide insight into the molecular basis of substrate recognition among the group II pyridoxal-5'-phosphate-dependent decarboxylases.
last changed 2014/03/20 11:44

B6db references