Isoschizomer

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In molecular biology, isoschizomers are pairs or groups of restriction enzymes which specifically recognize the same nucleotide sequence and cleave it in the same way. They generate identical fragments in a restriction digest because the restriction sites are identical.

Example of three isoschizomers
enzyme source Recognition sequence Restriction cut end up
Sph I Streptomyces phaeochromogenes 
5'-GCATGC-3'
3'-CGTACG-5'


5'-GCATG     C-3'
3'-C     GTACG-5'
3 'overhang with four bases
( sticky ends )
Pae I Pseudomonas aeruginosa
Bbu I Bacillus circulans

Further examples of pairs of isoschizomers are Ava II and Sin I, Cfo I and Hha I, Hpa II and Msp I. Apart from the fact that the restriction sequence is identical , there are often no major similarities between isoschizomers. These enzymes are isolated from different bacterial strains and often place different demands on optimal restriction digestion.

See also

literature