2yyg
From Proteopedia
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Crystal structure of the oxygenase component (HpaB) of 4-hydroxyphenylacetate 3-monooxygenase
Overview
The 4-hydroxyphenylacetate (4HPA) 3-monooxygenase is involved in the, initial step of the 4HPA degradation pathway and catalyzes 4HPA, hydroxylation to 3,4-dihydroxyphenylacetate. This enzyme consists of two, components, an oxygenase (HpaB) and a reductase (HpaC). To understand the, structural basis of the catalytic mechanism of HpaB, crystal structures of, HpaB from Thermus thermophilus HB8 were determined in three states: a, ligand-free form, a binary complex with FAD, and a ternary complex with, FAD and 4HPA. Structural analysis revealed that the binding and, dissociation of flavin are accompanied by conformational changes of the, loop between beta5 and beta6 and of the loop between beta8 and beta9, leading to preformation of part of the substrate-binding site (Ser-197 and, Thr-198). The latter loop further changes its conformation upon binding of, 4HPA and obstructs the active site from the bulk solvent. Arg-100 is, located adjacent to the putative oxygen-binding site and may be involved, in the formation and stabilization of the C4a-hydroperoxyflavin, intermediate.
About this Structure
2YYG is a Single protein structure of sequence from Thermus thermophilus with as ligand. Active as 4-hydroxyphenylacetate 3-monooxygenase, with EC number 1.14.13.3 Full crystallographic information is available from OCA.
Reference
Crystal Structure of the Oxygenase Component (HpaB) of the 4-Hydroxyphenylacetate 3-Monooxygenase from Thermus thermophilus HB8., Kim SH, Hisano T, Takeda K, Iwasaki W, Ebihara A, Miki K, J Biol Chem. 2007 Nov 9;282(45):33107-17. Epub 2007 Sep 5. PMID:17804419
Page seeded by OCA on Wed Jan 23 12:07:35 2008
