Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.2.1.17 (
lysozyme
)
21,489
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The nocardioform actinomycete Rhodococcus erythropolis has a characteristic cell wall structure. The cell wall is composed of arabinogalactan and mycolic acid and is highly resistant to the cell wall-lytic activity of
lysozyme
(
muramidase
). In order to improve the isolation of recombinant proteins from R. erythropolis host cells (N. Nakashima and T. Tamura, Biotechnol. Bioeng. 86:136-148, 2004), we isolated two mutants, L-65 and L-88, which are susceptible to
lysozyme
treatment. The
lysozyme
sensitivity of the mutants was complemented by expression of Corynebacterium glutamicum ltsA, which codes for an enzyme with glutamine amidotransferase activity that results from coupling of two reactions (a
glutaminase
activity and a synthetase activity). The
lysozyme
sensitivity of the mutants was also complemented by ltsA homologues from Bacillus subtilis and Mycobacterium tuberculosis, but the homologues from Streptomyces coelicolor and Escherichia coli did not complement the sensitivity. This result suggests that only certain LtsA homologues can confer
lysozyme
resistance. Wild-type recombinant LtsA from R. erythropolis showed
glutaminase
activity, but the LtsA enzymes from the L-88 and L-65 mutants displayed drastically reduced activity. Interestingly, an ltsA disruptant mutant, which expressed the mutated LtsA, changed from
lysozyme
sensitive to
lysozyme
resistant when NH(4)Cl was added into the culture media. The
glutaminase
activity of the LtsA mutants inactivated by site-directed mutagenesis was also restored by addition of NH(4)Cl, indicating that NH(3) can be used as an amide donor molecule. Taken together, these results suggest that LtsA is critically involved in mediating
lysozyme
resistance in R. erythropolis cells.
...
PMID:Characterization of LtsA from Rhodococcus erythropolis, an enzyme with glutamine amidotransferase activity. 1580 4
