4WKB

Crystal structure of Vibrio cholerae 5'-methylthioadenosine/S-adenosyl homocysteine nucleosidase (MTAN) complexed with methylthio-DADMe-Immucillin-A

4WKB の概要

• エントリーDOI: 10.2210/pdb4wkb/pdb
• 関連するPDBエントリー: 3DP9
• 分子名称: 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase, (3R,4S)-1-[(4-AMINO-5H-PYRROLO[3,2-D]PYRIMIDIN-7-YL)METHYL]-4-[(METHYLSULFANYL)METHYL]PYRROLIDIN-3-OL (3 entities in total)
• 機能のキーワード: hydrolase, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Vibrio cholerae serotype O1
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 53038.58

構造登録者

Cameron, S.A.,Thomas, K.,Almo, S.C.,Schramm, V.L. (登録日: 2014-10-02, 公開日: 2015-08-19, 最終更新日: 2023-09-27)

主引用文献

Thomas, K.,Cameron, S.A.,Almo, S.C.,Burgos, E.S.,Gulab, S.A.,Schramm, V.L.
Active site and remote contributions to catalysis in methylthioadenosine nucleosidases.
Biochemistry, 54:2520-2529, 2015

PubMed Abstract: 5'-Methylthioadenosine/S-adenosyl-l-homocysteine nucleosidases (MTANs) catalyze the hydrolysis of 5'-methylthioadenosine to adenine and 5-methylthioribose. The amino acid sequences of the MTANs from Vibrio cholerae (VcMTAN) and Escherichia coli (EcMTAN) are 60% identical and 75% similar. Protein structure folds and kinetic properties are similar. However, binding of transition-state analogues is dominated by favorable entropy in VcMTAN and by enthalpy in EcMTAN. Catalytic sites of VcMTAN and EcMTAN in contact with reactants differ by two residues; Ala113 and Val153 in VcMTAN are Pro113 and Ile152, respectively, in EcMTAN. We mutated the VcMTAN catalytic site residues to match those of EcMTAN in anticipation of altering its properties toward EcMTAN. Inhibition of VcMTAN by transition-state analogues required filling both active sites of the homodimer. However, in the Val153Ile mutant or double mutants, transition-state analogue binding at one site caused complete inhibition. Therefore, a single amino acid, Val153, alters the catalytic site cooperativity in VcMTAN. The transition-state analogue affinity and thermodynamics in mutant VcMTAN became even more unlike those of EcMTAN, the opposite of expectations from catalytic site similarity; thus, catalytic site contacts in VcMTAN are unable to recapitulate the properties of EcMTAN. X-ray crystal structures of EcMTAN, VcMTAN, and a multiple-site mutant of VcMTAN most closely resembling EcMTAN in catalytic site contacts show no major protein conformational differences. The overall protein architectures of these closely related proteins are implicated in contributing to the catalytic site differences.

PubMed: 25806409
DOI: 10.1021/bi501487w

実験手法

X-RAY DIFFRACTION (1.37 Å)