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Mycobacterium tuberculosis NAD+-dependent DNA ligase is selectively inhibited by glycosylamines compared with human DNA ligase I

IR@CDRI: CSIR-Central Drug Research Institute, Lucknow

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Field Value
 
Creator Srivastava, Sandeep Kumar
Dube, Divya
Tewari, Neetu
Dwivedi, Namrata
Tripathi, R P
Ravishankar, Ramachandran
 
Date 2007-12-24T11:09:53Z
2007-12-24T11:09:53Z
2005
 
Identifier Nucleic Acids Research, 2005, Vol. 33, No. 22, 7090–7101
http://hdl.handle.net/123456789/41
 
Description DNA ligases are important enzymes which catalyze the joining of nicks between adjacent bases of double-stranded DNA. NAD1-dependent DNA ligases (LigA) are essential in bacteria and are absent in humans. They have therefore been identified as novel, validated and attractive drug targets. Using virtual screening against an in-house database of compounds and our recently determined crystal structure of the NAD1 binding domain of the Mycobacterium tuberculosis LigA, we have identified N1, Nn-bis-(5-deoxy-a-D-xylofuranosylated) diamines as a novel class of inhibitors for this enzyme. Assays involving M.tuberculosis LigA, T4 ligase and human DNA ligase I show that these compounds specifically inhibit LigA from M.tuberculosis. In vitro kinetic and inhibition assays demonstrate that the compounds compete with NAD1 for binding and inhibit enzyme activity with IC50 values in the mM range. Docking studies rationalize the observed specificities and show that among several glycofuranosylated diamines, bis xylofuranosylated diamines with aminoalkyl and 1, 3-phenylene carbamoyl spacers mimic the binding modes of NAD1 with the enzyme. Assays involving LigA-deficient bacterial strains show that in vivo inhibition of ligase by the compounds causes the observed antibacterial activities. They also demonstrate that the compounds exhibit in vivo specificity for LigA over ATPdependent ligase. This class of inhibitors holds out the promise of rational development of new anti-tubercular agents.
 
Format 721833 bytes
application/pdf
 
Language en
 
Publisher Oxford University Press
 
Relation CDRI communication number 6784
 
Subject DNA ligases
NAD1-dependent
Mycobacterium tuberculosis
LigA
 
Title Mycobacterium tuberculosis NAD+-dependent DNA ligase is selectively inhibited by glycosylamines compared with human DNA ligase I
 
Type Article