1887

Abstract

A novel assay permitting the detection of UDPglucose 6-dehydrogenase activity in cell-free extracts obtained from phosphate-starved cultures of is described. The critical step, the separation of phosphate-starvation-induced exo-enzymes, phosphatases and phosphodiesterases from the cytoplasmic fraction containing the UDPglucose dehydrogenase, was achieved by protoplasting and removal of the periplasmic fraction by protoplast washing. Using this method, the following were unambiguously demonstrated: (i) the presence in the cytoplasm of an enzymic activity oxidizing UDPglucose to UDPglucuronic acid, and (ii) that detection of the activity in whole-cell-free extracts is prevented by the presence of ‘periplasmic' enzymes catalysing the degradation of the sugar nucleotides. With this method, several 168 mutants unable to synthesize teichuronic acid were examined. Strains inactivated in gene whose product shares homology with UDPglucose 6-dehydrogenase and GDPmannose 6-dehydrogenase from other organisms, were shown to lack UDPglucose 6-dehydrogenase activity. Anion exchange chromatography revealed that mutants deficient in lacked a cytoplasmic UDPglucuronate pool.

Loading

Article metrics loading...

/content/journal/micro/10.1099/13500872-145-5-1049
1999-05-01
2019-10-16
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/13500872-145-5-1049
Loading
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