In vitro mutagenesis and functional expression in Escherichia coli of a cDNA encoding the catalytic domain of human DNA ligase I - PubMed (original) (raw)

In vitro mutagenesis and functional expression in Escherichia coli of a cDNA encoding the catalytic domain of human DNA ligase I

K Kodama et al. Nucleic Acids Res. 1991.

Free PMC article

Abstract

Human cDNAs encoding fragments of DNA ligase I, the major replicative DNA ligase in mammalian cells, have been expressed as lacZ fusion proteins in Escherichia coli. A cDNA encoding the carboxyl-terminal catalytic domain of human DNA ligase I was able to complement a conditional-lethal DNA ligase mutation in E. coli as measured by growth of the mutant strain at the non-permissive temperature. Targeted deletions of the amino and carboxyl termini of the catalytic domain identified a minimum size necessary for catalytic function and a maximum size for optimal complementing activity in E. coli. The human cDNA was subjected to systematic site-directed mutagenesis in vitro and mutant polypeptides assayed for functional expression in the E. coli DNA ligase mutant. Such functional analysis of the active site of DNA ligase I identified specific residues required for the formation of an enzyme-adenylate reaction intermediate.

PubMed Disclaimer

References

    1. Proc Natl Acad Sci U S A. 1971 Oct;68(10):2559-63 - PubMed
    1. Nature. 1991 Jan 31;349(6308):429-31 - PubMed
    1. J Biol Chem. 1975 Nov 10;250(21):8438-44 - PubMed
    1. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463-7 - PubMed
    1. Nature. 1978 Aug 31;274(5674):891-3 - PubMed

MeSH terms

Substances

LinkOut - more resources