ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The gene nucM encoding a nuclease was cloned from a genomic library of Erwinia chrysanthemi. The nucM gene was subcloned, and mutagenized by insertion of a uidA-KanR cartridge. This mutation was introduced by recombination into the Erwinia chrysanthemi chromosome. The nucM mutant lost NucM activity when tested on a DNA plate after 24 hours, but still possessed secondary weak nuclease activity. The nucleotide sequence of nucM was determined. It presents a 798 bp open reading frame, coding for a 266-amino-acid protein, with a predicted molecular mass of 29 910 Da. The deduced NucM protein shows 59% sequence identity with the DNasel precursor from Vibrio cholerae. It contains a typical leader sequence. Experiments of cell fractionation showed that NucM is periplasmic In E. chrysanthemi. The transcription start has been determined by S1 mapping. The −10 and −35 regions do not show homology with consensus sequence of the promoters recognized by σ;70. In fact, The promoter seems to be dependent on the σ;70, but the first transcription nucleotide is unusually far from the −10 region. nucM seems to be expressed constitutively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.1993.tb01612.x
Permalink