Nucleotide sequence of the Dpn II DNA methylase gene of Streptococcus pneumoniae and its relationship to the dam gene of Escherichia coli

Journal Article · Mon Jul 01 04:00:00 EDT 1985 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.82.13.4468· OSTI ID:6085301

Mannarelli, B M; Balganesh, T S; Greenberg, B; Springhorn, S S; Lacks, S A

The structural gene (dpnM) for the Dpn II DNA methylase of Streptococcus pneumoniae, which is part of the Dpn II restriction system and methylates adenine in the sequence 5'-G-A-T-C-3', was identified by subcloning fragments of a chromosomal segment from a Dpn II-producing strain in an S. pneumoniae host/vector cloning system and demonstrating function of the gene also in Bacillus subtilis. Determination of the nucleotide sequence of the gene and adjacent DNA indicates that it encodes a polypeptide of 32,903 daltons. A putative promoter for transcription of the gene lies within a hundred nucleotides of the polypeptide start codon. Comparison of the coding sequence to that of the dam gene of Escherichia coli, which encodes a similar methylase, revealed 30% of the amino acid residues in the two enzymes to be identical. This homology presumably reflects a common origin of the two genes prior to the divergence of Gram-positive and Gram-negative bacteria. It is suggested that the restriction function of the gene is primitive, and that the homologous restriction system in E. coli has evolved to play an accessory role in heteroduplex DNA base mismatch repair.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 6085301
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 82:13; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550400* -- Genetics
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
CELL CONSTITUENTS
CHEMICAL REACTIONS
CLONING
DNA
DNA SEQUENCING
DNA-CLONING
ESCHERICHIA COLI
GENES
METHYLATION
MICROORGANISMS
MOLECULAR WEIGHT
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PEPTIDES
PLASMIDS
POLYPEPTIDES
PROTEINS
STREPTOCOCCUS
STRUCTURAL CHEMICAL ANALYSIS