Open AccessThe autolytic activity of the recombinant amidase of Staphylococcus saprophyticus is inhibited by its own recombinant GW repeats
Author(s) -
Hell Wolfgang,
Reichl Sylvia,
Anders Agnes,
Gatermann Sören
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(03)00647-5
Subject(s) - amidase , recombinant dna , autolysin , staphylococcus saprophyticus , escherichia coli , biology , tandem repeat , biochemistry , microbiology and biotechnology , enzyme , peptidoglycan , staphylococcus , gene , bacteria , genetics , staphylococcus aureus , genome
The Aas (autolysin/adhesin of Staphylococcus saprophyticus ) is a multifunctional surface protein containing two enzymatic domains an N ‐acetyl‐muramyl‐ l ‐alanine amidase, an endo‐β‐ N ‐acetyl‐ d ‐glucosaminidase, and two different regions of repetitive sequences, an N‐terminal and a C‐terminal repetitive domain. The C‐terminal repetitive domain is built up by the repeats R1, R2 and R3, which interconnect the putative active centers of the amidase and glucosaminidase. To investigate the influence of the C‐terminal repeats and the N‐terminal repeats on the amidase activity, the repetitive domains and fragments of them were cloned and expressed in Escherichia coli . The influence of the different fragments on the activity of the recombinant amidase of the Aas, consisting of the active center of the enzyme and repeat R1, was investigated in a turbidimetric microassay. The different fragments derived from the C‐terminal repeats inhibited the amidase activity, while the N‐terminal repeats did not influence the activity of the enzyme. The inhibiting activity increased with the number of GW repeats the recombinant fragment contained. Thus we conclude, that the C‐terminal GW repeats and not the N‐terminal repeats are necessary for the cell wall targeting and the autolytic function of the amidase.