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Frequently Asked Questions about Restriction Enzymes (1)

1. A restriction enzyme prototype, an isoschizomer and a neoschizomer - what's the difference?
    
   A prototype is the first or a newly discovered restriction enzyme that possesses a unique recognition specificity for DNA.
    
   Isoschizomers are restriction enzymes with the same specificity as prototypes but have been discovered subsequently.

   Note
   Isoschizomers are isolated from different bacterial strains and in many cases may require different reaction conditions (buffer, temperature). They possess different sensitivity to substrate methylation as well as contaminants. 

   For example:

   Prototype MboI	^GATC	sensitive to Dam methylation	reaction buffer R
   Isoschizomer Bsp143I	^GATC	NOT sensitive to Dam methylation	reaction buffer Tango™

   Neoschizomers are restriction enzymes that recognize the same nucleotide sequence as their prototype but cleave at a different site. In some special applications this is a very helpful feature. 

   For example:

   Prototype MaeII	A^CGT	produces DNA fragments with a 2-base 5' extension
   Neoschizomer TaiI	ACGT^	produces DNA fragments with a 4-base 3' extension
   Prototype ApaI	GGGCC^C	produces DNA fragments with a 4-base 3' extension
   Neoschizomer Bsp120I	G^GGCCC	produces DNA fragments with a 4-base 5' extension

     

2. How do I find the right specificity among Fermentas restriction enzyme or which Fermentas restriction enzyme corresponds to commercially available isoschizomers from other suppliers?
    
   There are four ways to help you find it:
    
   1. Refer to the comprehensive updated tables in the Fermentas 06/07 catalog:
   • Alphabetic List of Commercial Isoschizomers and Corresponding Fermentas Restriction Enzymes
   • Alphabetic List of Recognition Specificities
   • Alphabetic List of Restriction Enzymes Sorted by DNA Ends Generated
     

   2. Refer to the alphabetical index
     
   4. Contact Fermentas Technical Support:
       a) contact Fermentas distributor the nearest to your country 
       b) at info@fermentas.com
       c) at info@fermentas.lt

Updated 2007-01-17 16:46