title: Dimeric and tetrameric forms of enoyl-acyl carrier protein reductase from Bacillus cereus.
abstract: Enoyl-[acyl carrier protein] reductase (ENR) is an essential enzyme in type II fatty-acid synthesis that catalyzes the last step in each elongation cycle. Thus far FabI, FabL and FabK have been reported to carry out the reaction, with FabI being the most characterized. Some bacteria have more than one ENR, and Bacillus cereus has two (FabI and FabL) reported. Here, we have determined the crystal structures of the later in the apo form and in the ternary complex with NADP(+) and an indole naphthyridinone inhibitor. The two structures are almost identical, except for the three stretches that are disordered in the apo form. The apo form exists as a homo-dimer in both crystal and solution, while the ternary complex forms a homo-tetramer. The three stretches disordered in the apo structure are important in the cofactor and the inhibitor binding as well as in tetramer formation.
authors.affiliation: Life Sciences Division, Korea Institute of Science and Technology, 39-1 Hawolkok-dong, Sungbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Byung Hak
authors.initials: BH
authors.lastname: Ha
authors.forename: Kook-Han
authors.initials: KH
authors.lastname: Kim
authors.forename: Seung Kon
authors.initials: SK
authors.lastname: Hong
authors.forename: Key-Jung
authors.initials: KJ
authors.lastname: Shin
authors.forename: Se Won
authors.initials: SW
authors.lastname: Suh
authors.forename: Eunice Eunkyeong
authors.initials: EE
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001051:Apoenzymes / Q000737:chemistry; D001409:Bacillus cereus / Q000201:enzymology*; D018360:Crystallography, X-Ray; D050745:Enoyl-(Acyl-Carrier Protein) Reductase (NADPH, B-Specific) / Q000037:antagonists & inhibitors / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry; D008969:Molecular Sequence Data; D009249:NADP / Q000737:chemistry; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D013379:Substrate Specificity
chemical_list: D001051:Apoenzymes; D004791:Enzyme Inhibitors; D009249:NADP; D050745:Enoyl-(Acyl-Carrier Protein) Reductase (NADPH, B-Specific)