2q09

Publication Abstract from PubMed

Imidazolonepropionase (HutI) (imidazolone-5-propanote hydrolase, EC 3.5.2.7) is a member of the amidohydrolase superfamily and catalyzes the conversion of imidazolone-5-propanoate to N-formimino-L-glutamate in the histidine degradation pathway. We have determined the three-dimensional crystal structures of HutI from Agrobacterium tumefaciens (At-HutI) and an environmental sample from the Sargasso Sea Ocean Going Survey (Es-HutI) bound to the product [ N-formimino-L-glutamate (NIG)] and an inhibitor [3-(2,5-dioxoimidazolidin-4-yl)propionic acid (DIP)], respectively. In both structures, the active site is contained within each monomer, and its organization displays the landmark feature of the amidohydrolase superfamily, showing a metal ligand (iron), four histidines, and one aspartic acid. A catalytic mechanism involving His265 is proposed on the basis of the inhibitor-bound structure. This mechanism is applicable to all HutI forms.

A common catalytic mechanism for proteins of the HutI family.,Tyagi R, Eswaramoorthy S, Burley SK, Raushel FM, Swaminathan S Biochemistry. 2008 May 20;47(20):5608-15. Epub 2008 Apr 29. PMID:18442260^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.