Summary: Polynucleotide phosphorylase activity was demonstrated in free-living and the symbiotic bacteroid forms of and in free-living . Crude extracts of -28 catalysed the polymerization of 3.0 μmol ADP (mg protein) h. The polynucleotide phosphorylase activity of symbiotic was about 50% of that of free-living and remained almost constant throughout the development of the nodules. Partially-purified fractions of free-living -28 catalysed the polymerization of ribonucleoside diphosphates, the phosphorolysis of synthetic homopolymers and natural heteropolymers, and the β-phosphate exchange reaction. The enzyme had a pH optimum of 8.0 and had an obligatory requirement for Mg for maximum activity. The phosphorylase was not highly primer-dependent, had low specificity for guanosine-containing substrates, and exhibited cooperative-type kinetics.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error