1hq6
From Proteopedia
STRUCTURE OF PYRUVOYL-DEPENDENT HISTIDINE DECARBOXYLASE AT PH 8
Overview
Histidine decarboxylase (HDC) from Lactobacillus 30a produces histamine that is essential to counter waste acids, and to optimize cell growth. The HDC trimer is active at low pH and inactive at neutral to alkaline pH. We have solved the X-ray structure of HDC at pH 8 and revealed the novel mechanism of pH regulation. At high pH helix B is unwound, destroying the substrate binding pocket. At acid pH the helix is stabilized, partly through protonation of Asp198 and Asp53 on either side of the molecular interface, acting as a proton trap. In contrast to hemoglobin regulation, pH has a large effect on the tertiary structure of HDC monomers and relatively little or no effect on quaternary structure.
About this Structure
1HQ6 is a Protein complex structure of sequences from Lactobacillus sp.. Full crystallographic information is available from OCA.
Reference
pH-induced structural changes regulate histidine decarboxylase activity in Lactobacillus 30a., Schelp E, Worley S, Monzingo AF, Ernst S, Robertus JD, J Mol Biol. 2001 Mar 2;306(4):727-32. PMID:11243783 Page seeded by OCA on Fri May 2 19:06:47 2008
