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Crystal structure of NaeI-an evolutionary bridge between DNA endonuclease and topoisomerase.

ABSTRACT: NAE:I is transformed from DNA endonuclease to DNA topoisomerase and recombinase by a single amino acid substitution. The crystal structure of NAE:I was solved at 2.3 A resolution and shows that NAE:I is a dimeric molecule with two domains per monomer. Each domain contains one potential DNA recognition motif corresponding to either endonuclease or topoisomerase activity. The N-terminal domain core folds like the other type II restriction endonucleases as well as lambda-exonuclease and the DNA repair enzymes MutH and Vsr, implying a common evolutionary origin and catalytic mechanism. The C-terminal domain contains a catabolite activator protein (CAP) motif present in many DNA-binding proteins, including the type IA and type II topoisomerases. Thus, the NAE:I structure implies that DNA processing enzymes evolved from a few common ancestors. NAE:I may be an evolutionary bridge between endonuclease and DNA processing enzymes.

SUBMITTER: Huai Q

PROVIDER: S-EPMC203366 | biostudies-literature | 2000 Jun

REPOSITORIES: biostudies-literature

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Crystal structure of NaeI-an evolutionary bridge between DNA endonuclease and topoisomerase.

Huai Q Q Colandene J D JD Chen Y Y Luo F F Zhao Y Y Topal M D MD Ke H H

The EMBO journal 20000601 12

NAE:I is transformed from DNA endonuclease to DNA topoisomerase and recombinase by a single amino acid substitution. The crystal structure of NAE:I was solved at 2.3 A resolution and shows that NAE:I is a dimeric molecule with two domains per monomer. Each domain contains one potential DNA recognition motif corresponding to either endonuclease or topoisomerase activity. The N-terminal domain core folds like the other type II restriction endonucleases as well as lambda-exonuclease and the DNA rep ...[more]

PMID: 10856254

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