1GU9

Crystal Structure of Mycobacterium tuberculosis Alkylperoxidase AhpD

1GU9 の概要

• エントリーDOI: 10.2210/pdb1gu9/pdb
• 分子名称: ALKYLHYDROPEROXIDASE D (2 entities in total)
• 機能のキーワード: oxidoreductase, alkylhydroperoxidase, tuberculosis
• 由来する生物種: MYCOBACTERIUM TUBERCULOSIS
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 227306.46

構造登録者

Nunn, C.M.,Djordjevic, S.,Hillas, P.J.,Nishida, C.,Ortiz de Montellano, P.R. (登録日: 2002-01-24, 公開日: 2002-02-14, 最終更新日: 2024-10-09)

主引用文献

Nunn, C.M.,Djordjevic, S.,Hillas, P.J.,Nishida, C.,Ortiz de Montellano, P.R.
The Crystal Structure of Mycobacterium Tuberculosis Alkylhydroperoxidase Ahpd, a Potential Target for Antitubercular Drug Design
J.Biol.Chem., 277:20033-, 2002

PubMed Abstract: The resistance of Mycobacterium tuberculosis to isoniazid is commonly linked to inactivation of a catalase-peroxidase, KatG, that converts isoniazid to its biologically active form. Loss of KatG is associated with elevated expression of the alkylhydroperoxidases AhpC and AhpD. AhpD has no sequence identity with AhpC or other proteins but has alkylhydroperoxidase activity and possibly additional physiological activities. The alkylhydroperoxidase activity, in the absence of KatG, provides an important antioxidant defense. We have determined the M. tuberculosis AhpD structure to a resolution of 1.9 A. The protein is a trimer in a symmetrical cloverleaf arrangement. Each subunit exhibits a new all-helical protein fold in which the two catalytic sulfhydryl groups, Cys-130 and Cys-133, are located near a central cavity in the trimer. The structure supports a mechanism for the alkylhydroperoxidase activity in which Cys-133 is deprotonated by a distant glutamic acid via the relay action of His-137 and a water molecule. The cysteine then reacts with the peroxide to give a sulfenic acid that subsequently forms a disulfide bond with Cys-130. The crystal structure of AhpD identifies a new protein fold relevant to members of this protein family in other organisms. The structural details constitute a potential platform for the design of inhibitors of potential utility as antitubercular agents and suggest that AhpD may have disulfide exchange properties of importance in other areas of M. tuberculosis biology.

PubMed: 11914371
DOI: 10.1074/JBC.M200864200

実験手法

X-RAY DIFFRACTION (1.9 Å)