1HNJ

CRYSTAL STRUCTURE OF BETA-KETOACYL-ACP SYNTHASE III + MALONYL-COA

Summary for 1HNJ

• Entry DOI: 10.2210/pdb1hnj/pdb
• Related: 1hn9 1hnd 1hnh 1hnk
• Descriptor: BETA-KETOACYL-ACYL CARRIER PROTEIN SYNTHASE III, PHOSPHATE ION, MALONYL-COENZYME A, ... (4 entities in total)
• Functional Keywords: fabh, transferase
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P0A6R0
• Total number of polymer chains: 1
• Total formula weight: 34495.58

Authors

Qiu, X.,Janson, C.A.,Smith, W.W.,Head, M.,Lonsdale, J.,Konstantinidis, A.K. (deposition date: 2000-12-07, release date: 2000-12-27, Last modification date: 2024-02-07)

Primary citation

Qiu, X.,Janson, C.A.,Smith, W.W.,Head, M.,Lonsdale, J.,Konstantinidis, A.K.
Refined structures of beta-ketoacyl-acyl carrier protein synthase III.
J.Mol.Biol., 307:341-356, 2001

PubMed Abstract: beta-Ketoacyl-acyl carrier protein synthase III (FabH) is a condensing enzyme that plays central roles in fatty acid biosynthesis. Three-dimensional structures of E. coli FabH in the presence and absence of ligands have been refined to 1.46 A resolution. The structures of improved accuracy revealed detailed interactions involved in ligand binding. These structures also provided new insights into the FabH mechanism, e.g. the possible role of a water or hydroxyl anion in Cys112 deprotonation. A structure of the apo enzyme uncovered large conformational changes in the active site, exemplified by the disordering of four essential loops (84-86, 146-152, 185-217 and 305-307) and the movement of catalytic residues (Cys112 and His244). The disordering of the loops leads to greater than 50 % reduction in the FabH dimer interface, suggesting a dynamic nature for an unusually large portion of the dimer interface. The existence of a large solvent-accessible channel in the dimer interface as well as two cis-peptides (cis-Pro88 and cis-Phe308) in two of the disordered loops may explain the observed structural instabilities.

PubMed: 11243824
DOI: 10.1006/jmbi.2000.4457

Experimental method

X-RAY DIFFRACTION (1.46 Å)