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Mechanism of DNA cleavage by the DNA/RNA-non-specific Anabaena sp. PCC 7120 endonuclease NucA and its inhibition by NuiA

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dc.contributor.author Meiss G.
dc.contributor.author Gimadutdinow O.
dc.contributor.author Haberland B.
dc.contributor.author Pingoud A.
dc.date.accessioned 2018-09-17T20:22:45Z
dc.date.available 2018-09-17T20:22:45Z
dc.date.issued 2000
dc.identifier.issn 0022-2836
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/133422
dc.description.abstract A structural model of the DNA/RNA non-specific endonuclease NucA from Anabaena sp. PCC7120 that has been obtained on the basis of the three-dimensional structure of the related Serratia nuclease, suggests that the overall architecture of the active site including amino acid residues H124, N155 and E163 (corresponding to H89, N119 and E127 in Serratia nuclease) is similar in both nucleases. Substitution of these residues by alanine leads to a large reduction in activity (<0.1%), similarly as observed for Serratia nuclease demonstrating that both enzymes share a similar mechanism of catalysis with differences only in detail. NucA is inhibited by its specific polypeptide inhibitor with a K1 value in the subpicomolar range, while the related Serratia nuclease at nanomolar concentrations is only inhibited at an approximately 1000-fold molar excess of NuiA. The artificial chromophoric substrate deoxythymidine 3',5'-bis-(p-nitrophenyl phosphate) is cleaved by NucA as well as by Serratia nuclease. Cleavage of this analogue by NucA, however, is not inhibited by NuiA, suggesting that small molecules gain access to the active site of NucA in the enzyme-inhibitor complex under conditions where cleavage of DNA substrates is completely inhibited. The active site residue E163 seems to be the main target amino acid for inhibition of NucA by NuiA, but R93, R122 and R167 (corresponding to K55, R87, R131 in Serratia nuclease) are also involved in the NucA/NuiA interaction. NuiA deletion mutants show that the structural integrity of the N and C-terminal region of the inhibitor is important for complex formation with NucA and inhibition of nuclease activity. Based on these results a mechanism of DNA cleavage by NucA and its inhibition by NuiA is proposed. (C) 2000 Academic Press.
dc.relation.ispartofseries Journal of Molecular Biology
dc.subject Enzyme mechanism
dc.subject Inhibitor
dc.subject Nuclease
dc.subject Structural model
dc.title Mechanism of DNA cleavage by the DNA/RNA-non-specific Anabaena sp. PCC 7120 endonuclease NucA and its inhibition by NuiA
dc.type Article
dc.relation.ispartofseries-issue 2
dc.relation.ispartofseries-volume 297
dc.collection Публикации сотрудников КФУ
dc.relation.startpage 521
dc.source.id SCOPUS00222836-2000-297-2-SID0034708328

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  • Публикации сотрудников КФУ Scopus [20180]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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