1WEF

Catalytic Domain Of Muty From Escherichia Coli K20A Mutant

1WEF の概要

• エントリーDOI: 10.2210/pdb1wef/pdb
• 関連するPDBエントリー: 1WEG 1WEI
• 分子名称: A/G-specific adenine glycosylase, IRON/SULFUR CLUSTER (3 entities in total)
• 機能のキーワード: hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 25342.53

構造登録者

Hitomi, K.,Arvai, A.S.,Tainer, J.A. (登録日: 2004-05-25, 公開日: 2004-09-21, 最終更新日: 2024-05-29)

主引用文献

Manuel, R.C.,Hitomi, K.,Arvai, A.S.,House, P.G.,Kurtz, A.J.,Dodson, M.L.,McCullough, A.K.,Tainer, J.A.,Lloyd, R.S.
Reaction intermediates in the catalytic mechanism of Escherichia coli MutY DNA glycosylase
J.Biol.Chem., 279:46930-46939, 2004

PubMed Abstract: The Escherichia coli adenine DNA glycosylase, MutY, plays an important role in the maintenance of genomic stability by catalyzing the removal of adenine opposite 8-oxo-7,8-dihydroguanine or guanine in duplex DNA. Although the x-ray crystal structure of the catalytic domain of MutY revealed a mechanism for catalysis of the glycosyl bond, it appeared that several opportunistically positioned lysine side chains could participate in a secondary beta-elimination reaction. In this investigation, it is established via site-directed mutagenesis and the determination of a 1.35-A structure of MutY in complex with adenine that the abasic site (apurinic/apyrimidinic) lyase activity is alternatively regulated by two lysines, Lys142 and Lys20. Analyses of the crystallographic structure also suggest a role for Glu161 in the apurinic/apyrimidinic lyase chemistry. The beta-elimination reaction is structurally and chemically uncoupled from the initial glycosyl bond scission, indicating that this reaction occurs as a consequence of active site plasticity and slow dissociation of the product complex. MutY with either the K142A or K20A mutation still catalyzes beta and beta-delta elimination reactions, and both mutants can be trapped as covalent enzyme-DNA intermediates by chemical reduction. The trapping was observed to occur both pre- and post-phosphodiester bond scission, establishing that both of these intermediates have significant half-lives. Thus, the final spectrum of DNA products generated reflects the outcome of a delicate balance of closely related equilibrium constants.

PubMed: 15326180
DOI: 10.1074/jbc.M403944200

実験手法

X-RAY DIFFRACTION (1.9 Å)