Work

A Common Catalytic Mechanism for Proteins of the HutI Family

Year: 2008

Type: article

Abstract: 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.

Source: Biochemistry

DOI: 10.1021/bi800180g

Authors: Rajiv Tyagi, Subramaniam Eswaramoorthy, Stephen K. Burley, Frank M. Raushel, Subramanyam Swaminathan

Institutions: Brookhaven National Laboratory, Texas A&M University

Language: English

Topic: Enzyme Structure and Function

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Awards: DECIPHERING ENZYME SPECIFICITY, G6748990862, NYSGXRC:A Large Scale Center for the PSI, G858275722