Three-dimensional structural of the bifunctional enzyme N-(5'-phosphoribosyl)anthranilate isomerase-indole-3-glycerol-phosphate synthase from Escherichia coli

Journal Article · Sat Aug 01 04:00:00 EDT 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.16.5690· OSTI ID:5235825

Priestle, J P; Gruetter, M G; White, J L; Vincent, M G; Kania, M; Wilson, E; Jardetzky, T S; Kirschner, K; Jansonius, J N

N-(5'-Phosphoribosyl) anthranilate isomerase-indole-3-glycerol-phosphate synthase from Escherichia coli is a monomeric bifunctional enzyme of M/sub r/ 49,500 that catalyzes two sequential reactions in the biosynthesis of tryptophan. The three-dimensional structure of the enzyme has been determined at 2.8-A resolution by x-ray crystallography. The two catalytic activities reside on distinct functional domains of similar folding, that of an eightfold parallel ..beta..-barrel with ..cap alpha..-helices on the outside connecting the ..beta..-strands. Both active sites were located with an iodinated substrate analogue and found to be in depressions on the surface of the domains created by the outward-curving hoops between the carboxyl termini of the ..beta..-sheet strands and the subsequent ..cap alpha..-helices. They do not face each other, making channeling of the substrate between active sties virtually impossible. Despite the structural similarity of the two domains, no significant sequence homology was found when topologically equivalent residues were compared

• Research Organization: Biozentrum der Universitaet Basel (Switzerland)
• OSTI ID: 5235825
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 84:16; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
AROMATICS
AZAARENES
AZOLES
BACTERIA
BIOSYNTHESIS
CARBOXYLIC ACIDS
COHERENT SCATTERING
CRYSTALLOGRAPHY
DIFFRACTION
ENZYMES
ESCHERICHIA COLI
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INDOLES
ISOMERASES
MICROORGANISMS
MOLECULAR STRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRROLES
SCATTERING
SYNTHESIS
TRYPTOPHAN
X-RAY DIFFRACTION