4XVX

Crystal structure of an acyl-ACP dehydrogenase

「4M6Z」から置き換えられました

4XVX の概要

• エントリーDOI: 10.2210/pdb4xvx/pdb
• 分子名称: Acyl-[acyl-carrier-protein] dehydrogenase MbtN, 3,6,9,12,15,18-HEXAOXAICOSANE-1,20-DIOL, DIHYDROFLAVINE-ADENINE DINUCLEOTIDE, ... (5 entities in total)
• 機能のキーワード: structural genomics, tb structural genomics consortium, tbsgc, rossmann fold, acyl-acp binding, dehydrogenation, oxidoreductase
• 由来する生物種: Mycobacterium tuberculosis
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 85016.36

構造登録者

Chai, A.,Johnston, J.M.,Bunker, R.D.,Lott, J.S.,Baker, E.N.,TB Structural Genomics Consortium (TBSGC) (登録日: 2015-01-28, 公開日: 2015-02-11, 最終更新日: 2023-09-27)

主引用文献

Chai, A.F.,Bulloch, E.M.,Evans, G.L.,Lott, J.S.,Baker, E.N.,Johnston, J.M.
A covalent adduct of MbtN, an acyl-ACP dehydrogenase from Mycobacterium tuberculosis, reveals an unusual acyl-binding pocket.
Acta Crystallogr.,Sect.D, 71:862-872, 2015

PubMed Abstract: Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis. Access to iron in host macrophages depends on iron-chelating siderophores called mycobactins and is strongly correlated with Mtb virulence. Here, the crystal structure of an Mtb enzyme involved in mycobactin biosynthesis, MbtN, in complex with its FAD cofactor is presented at 2.30 Å resolution. The polypeptide fold of MbtN conforms to that of the acyl-CoA dehydrogenase (ACAD) family, consistent with its predicted role of introducing a double bond into the acyl chain of mycobactin. Structural comparisons and the presence of an acyl carrier protein, MbtL, in the same gene locus suggest that MbtN acts on an acyl-(acyl carrier protein) rather than an acyl-CoA. A notable feature of the crystal structure is the tubular density projecting from N(5) of FAD. This was interpreted as a covalently bound polyethylene glycol (PEG) fragment and resides in a hydrophobic pocket where the substrate acyl group is likely to bind. The pocket could accommodate an acyl chain of 14-21 C atoms, consistent with the expected length of the mycobactin acyl chain. Supporting this, steady-state kinetics show that MbtN has ACAD activity, preferring acyl chains of at least 16 C atoms. The acyl-binding pocket adopts a different orientation (relative to the FAD) to other structurally characterized ACADs. This difference may be correlated with the apparent ability of MbtN to catalyse the formation of an unusual cis double bond in the mycobactin acyl chain.

PubMed: 25849397
DOI: 10.1107/S1399004715001650

実験手法

X-RAY DIFFRACTION (2.3 Å)