Team:Imperial College London/M3/Genetic/DpnTaq

DpnII

DpnII comes from Streptococccus Pneumonia.

DpnII recognises the sequence GATC and cleave before G.

Cells of Streptococccus Pneumonia contain either DpnII, or the more well-known DpnI as part of their restriction machinery. Both recognise the same sequence of GATC. However, DpnII only acts on the unmethylated strand, as opposed to DpnI that only cleaves methylated strands.

The DpnII restriction cassette contains 2 methylases and 1 endonuclease.

TaqI

TaqI comes from the thermophile thermus aquaticus.

TaqI recognises the sequence TCGA and cleaves after T.

Interestingly, the TaqI gene contains 7 TaqI sites, probably important in autoregulation of TaqI expression.

The TaqI restriction cassette contains 1 methylase and 1 endonuclease.

References

http://www.uniprot.org/uniprot
Uniprot ID P09357
Uniprot ID P14386

Lacks SA, Mannarelli BM, Springhorn SS, Greenberg B Genetic basis of the complementary DpnI and DpnII restriction systems of S. pneumoniae: an intercellular cassette mechanism. Cell. 1986 Sep 26;46(7):993-1000.

Barton E.Slatko*, Jack S.Benner, Tineka Jager-Quinton, Laurie S.Moran, Timothy G.Simcox, Elizabeth M.Van Cott and Geoffrey G.Wilson. (1987) Cloning, sequencing and expression of the Taq I restriction-modification system. Nucleic Acids Research. Volume 15 Number 23