Open AccessEnzyme–adenylate structure of a bacterial ATP‐dependent DNA ligase with a minimized DNA‐binding surface
Author(s) -
Williamson Adele,
Rothweiler Ulli,
Schrøder Leiros HannaKirsti
Publication year - 2014
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s1399004714021099
Subject(s) - dna ligase , dna ligases , circular bacterial chromosome , dna clamp , dna , biochemistry , biology , in vitro recombination , phosphodiester bond , sticky and blunt ends , okazaki fragments , enzyme , prokaryotic dna replication , dna replication , eukaryotic dna replication , molecular cloning , rna , complementary dna , gene , reverse transcriptase
DNA ligases are a structurally diverse class of enzymes which share a common catalytic core and seal breaks in the phosphodiester backbone of double‐stranded DNA via an adenylated intermediate. Here, the structure and activity of a recombinantly produced ATP‐dependent DNA ligase from the bacterium Psychromonas sp. strain SP041 is described. This minimal‐type ligase, like its close homologues, is able to ligate singly nicked double‐stranded DNA with high efficiency and to join cohesive‐ended and blunt‐ended substrates to a more limited extent. The 1.65 Å resolution crystal structure of the enzyme–adenylate complex reveals no unstructured loops or segments, and suggests that this enzyme binds the DNA without requiring full encirclement of the DNA duplex. This is in contrast to previously characterized minimal DNA ligases from viruses, which use flexible loop regions for DNA interaction. The Psychromonas sp. enzyme is the first structure available for the minimal type of bacterial DNA ligases and is the smallest DNA ligase to be crystallized to date.