Identification of base mismatches recognized by the heteroduplex-DNA-repair system of Streptococcus pneumoniae

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Cell; (United States)

DOI:https://doi.org/10.1016/0092-8674(82)90126-X· OSTI ID:5606071

Lacks, S A; Dunn, J J; Greenberg, B

The susceptibility to repair of particular base mismatches by the hex system of Streptococcus pneumoniae was examined by comparison of the nucleotide sequence of the wild-type and eight mutant alleles of the malM gene. A detailed restriction map was constructed for pLS70, and the nucleotide sequence was determined for its 3475 bp chromosomal insert, which contains the entire malM gene (encoding amylomaltase), portions of malX and malP (encoding a membrane protein and a phosphorylase, respectively) and a control region. Transition mismatches were highly susceptible to repair; transversion mismatches, much less so. A mismatch caused by a single-nucleotide deletion was reparable but mismatches with longer deletions were not. The hex system also reduced spontaneous reversion of mutations corresponding to transitions. It is suggested that recognition of donor or nascent DNA strands by the hex system depends on single-strand breaks in the target strand, and that the role of DNA methylation in mismatch repair of Escherichia coli can be accommodated to this model.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 5606071
• Journal Information: Cell; (United States), Journal Name: Cell; (United States) Vol. 31; ISSN CELLB
• Country of Publication: United States
• Language: English

Related Subjects

550400* -- Genetics
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHROMOSOMAL ABERRATIONS
DNA
GENES
GENETIC MAPPING
MAPPING
METHYLATION
MICROORGANISMS
MUTATIONS
NUCLEIC ACIDS
NUCLEOTIDES
ORGANIC COMPOUNDS
PLASMIDS
RECOVERY
REPAIR
STRAND BREAKS
STREPTOCOCCUS