A simple and rapid method for screening bacteria for type II restriction endonucleases: enzymes inAphanothece halophytica

✍ Scribed by Philip R. Whitehead; Nigel L. Brown

• Publisher: Springer
• Year: 1985
• Tongue: English
• Weight: 689 KB
• Volume: 141
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00446742

✦ Synopsis

A method is described which allows a large number of bacterial strains to be rapidly and easily screened for the presence of site-specific endonucleases. The method involves selective permeabilization of the bacterial cell and analysis of the exuded material. Type II restriction endonucleases from cyanobacteria and Gram-negative eubacteria have been detected and new enzymes have been found. The method should be widely applicable and easy to modify for use in genera other than those tested. Three-site-specific endonuclease activities, detected by this method in Aphanothece halophytica PCC 7412, were purified and their recognition and cleavage specificities were determined AhaI and AhalI recognise and cleave the same DNA sequences as CauII and A cyI respectively; the specificity of AhalII (TTTIAAA) has been reported previously (Whitehead and Brown, 1982, FEBS Letters 143 : 296-300).