Dam dcm strain

The dam dcm strain is a strain of the nonpathogenic E. coli K-12 bacteria with functional dam and dcm genes.^[1]

The methylase encoded by the dam gene (Dam methylase) transfers a methyl group from S-adenosylmethionine to adenine residues in the sequence GATC.^[2][3] The Dcm methylase (encoded by the dcm gene) methylated the internal cytosine residues in the sequences CCAGG and CCTGG.^[2][4]

Restriction enzyme DpnI can recognize 5'-GmeATC-3'sites and digest the methylated DNA.

List of some Dam- strains - JM110 - GM2929 - INV110

See also

• DNA replication
• mismatch repair

References

1. ^ Bale A, d'Alarcao M, Marinus MG (February 1979). "Characterization of DNA adenine methylation mutants of Escherichia coli K12". Mutat. Res. 59 (2): 157–65. PMID 375073. 
2. ^ ^{a b} Marinus MG, Morris NR (June 1973). "Isolation of deoxyribonucleic acid methylase mutants of Escherichia coli K-12". J. Bacteriol. 114 (3): 1143–50. PMC 285375. PMID 4576399. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=285375. 
3. ^ Geier GE, Modrich P (February 1979). "Recognition sequence of the dam methylase of Escherichia coli K12 and mode of cleavage of Dpn I endonuclease". J. Biol. Chem. 254 (4): 1408–13. PMID 368070. 
4. ^ May MS, Hattman S (August 1975). "Analysis of bacteriophage deoxyribonucleic acid sequences methylated by host- and R-factor-controlled enzymes". J. Bacteriol. 123 (2): 768–70. PMC 235790. PMID 1097428. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=235790. 

External links

• "Making unmethylated (Dam- Dcm-) DNA". New England Biolabs. http://www.neb.com/nebecomm/tech_reference/restriction_enzymes/making_unmethylated_dna.asp. Retrieved 2010-11-01.