Restriction endonucleases from Herpetosiphon giganteus: an example of the evolution of DNA recognition specificity?
AUTOR(ES)
Whitehead, P R
RESUMO
We describe the partial purification and characterisation of five Type II restriction endonucleases from two strains of Herpetosiphon giganteus. One of the activities, HgiJII, was the first enzyme found that cleaves DNA at the family of related sequences 5'-G-R-G-C-Y/C-3'. This enzyme may be related to the enzyme HgiAI from a different strain of the same species, and which cleaves at the sites 5'-G-W-G-C-W/C-3'. We have shown that DNAs from the strains producing HgiAI and HgiJII are resistant to both of these restriction endonucleases. The remaining four enzymes described here share recognition and cleavage specificities with other restriction endonucleases. The evolution of Type II restriction-modification systems and their role in vivo are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=311715Documentos Relacionados
- Eight new restriction endonucleases fröm Herpetosiphon giganteus--divergent evolution in a family of enzymes.
- Stepwise cloning and molecular characterization of the HgiDI restriction-modification system from Herpetosiphon giganteus Hpa2.
- Evolution of divergent DNA recognition specificities in VDE homing endonucleases from two yeast species
- Role of thymidine residues in DNA recognition by the EcoRI and EcoRV restriction endonucleases.
- Changing the recognition specificity of a DNA-methyltransferase by in vitro evolution