Linked Life Data

8830261

Source:http://linkedlifedata.com/resource/pubmed/id/8830261

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1996-10-17
pubmed:databankReference
pubmed:abstractText
We describe the characterization of a mutant strain of Streptococcus pneumoniae previously isolated on the basis of its sensitivity to Methyl Methane Sulphonate (MMS). The mutant strain also exhibited increased sensitivity to UV light and to X-rays, together with a reduced capacity for recombination and Hex-mediated generalized mismatch repair. We show that the original mutant contains two unlinked mutations in the mmsA and in the pms genes. The mmsA wild-type region was cloned and the nucleotide sequence of the mmsA gene was determined. mmsA encodes a polypeptide of 671 amino acids related to a large family of DNA-RNA helicases, with the highest similarity to Escherichia coli RecG, a protein involved in the branch migration of Holliday junctions. A plasmid carrying the intact mmsA coding region was shown to restore UV resistance to E. coli recG mutant strains. An mmsA-null mutant constructed by insertion of a chloramphenicol-resistance gene exhibited a 25-fold reduction in recombination during transformation. We suggest that MmsA recognizes and branch migrates three-strand transformation intermediates to extend donor-recipient heteroduplex regions. The mmsA-null mutant exhibited the other phenotypes of the original mutant, apart from mismatch-repair deficiency and, in addition, an alteration in colony-forming ability was noticed. In the pms mutant background, all phenotypes caused by the mmsA mutation were attenuated. Therefore, the pms mutation, although it affected mismatch repair and, to some extent, DNA repair and recombination, acted as a suppressor of the mmsA mutation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1035-45
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
The mmsA locus of Streptococcus pneumoniae encodes a RecG-like protein involved in DNA repair and in three-strand recombination.
pubmed:affiliation
Microbiologie et Génétique Moléculaire CNRS-UPR 9007, Université Paul Sabatier, Toulouse, France.
pubmed:publicationType
Journal Article