1b04
From Proteopedia
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STRUCTURE OF THE ADENYLATION DOMAIN OF AN NAD+ DEPENDENT LIGASE
Overview
BACKGROUND: DNA ligases catalyse phosphodiester bond formation between, adjacent bases in nicked DNA, thereby sealing the nick. A key step in the, catalytic mechanism is the formation of an adenylated DNA intermediate., The adenyl group is derived from either ATP (in eucaryotes and archaea) or, NAD+4 (in bacteria). This difference in cofactor specificity suggests that, DNA ligase may be a useful antibiotic target. RESULTS: The crystal, structure of the adenylation domain of the NAD+-dependent DNA ligase from, Bacillus stearothermophilus has been determined at 2.8 A resolution., Despite a complete lack of detectable sequence similarity, the fold of the, central core of this domain shares homology with the equivalent region of, ATP-dependent DNA ligases, providing strong evidence for the location of, the NAD+-binding site. CONCLUSIONS: Comparison of the structure of the, NAD+4-dependent DNA ligase with that of ATP-dependent ligases and, mRNA-capping enzymes demonstrates the manifold utilisation of a conserved, nucleotidyltransferase domain within this family of enzymes. Whilst this, conserved core domain retains a common mode of nucleotide binding and, activation, it is the additional domains at the N terminus and/or the C, terminus that provide the alternative specificities and functionalities in, the different members of this enzyme superfamily.
About this Structure
1B04 is a Single protein structure of sequence from Geobacillus stearothermophilus. Active as DNA ligase (NAD(+)), with EC number 6.5.1.2 Full crystallographic information is available from OCA.
Reference
Structure of the adenylation domain of an NAD+-dependent DNA ligase., Singleton MR, Hakansson K, Timson DJ, Wigley DB, Structure. 1999 Jan 15;7(1):35-42. PMID:10368271
Page seeded by OCA on Tue Nov 20 11:14:47 2007
