Psi I

Description

Recognition site and hydrolysis position:

Source: Pseudomonas species-SE-G49
Unit definition:
One unit of the enzyme is the amount required to hydrolyze 1 μg of Lambda DNA in 1 hour at 37°C in a total reaction volume of 50 μl.
Assayed on:
Lambda DNA
Optimal SE-buffer: SE-buffer B
Enzyme activity (%):

Storage conditions: 10 mM Tris-HCl (pH 7.5); 200 mM KCl; 0.1 mM EDTA; 7 mM 2-mercaptoethanol; 200 μg/ml BSA; and 50% glycerol; Store at -20°C.
Ligations:
After 5-fold overdigestion with enzyme about 50% of the DNA fragments can be ligated and of these 95% can be recut.
Non-specific hydrolisis:
No nonspecific activity was detected after incubation of 1 μg of Lambda DNA with 20 u.a. of enzyme for 16 hours at 37°C. Reagents Supplied with Enzyme 10 X SE-buffer B
Reagents Supplied with Enzyme:
Methylation sensitivity: not tested
Notes: The minimum number of units that resulted in complete digestion of 1 μg of substrate DNA in 16 hours is 0,25.
References:
Abdurashitov, M.A., Belichenko, O.A., Lebedeva, N.A., Degtyarev, S.Kh. Biokhimiia 64: 574-576 (1999).