Characteristics of PA2783 and its homology to other proteins. (A) Amino acid sequence of the predicted protein encoded by PA2783. The 602 aa sequence of PA2783 is shown. The following features are indicated: (1) Pseudomonas aeruginosa type I export signal and cleavage site, aa 1 to aa 24, in black and underlined, with the cleavage site at AQA-AP; (2) M72 family peptidase domain, aa 27 to aa 204, in red; (3) the conserved signature HEXXHXXGLRH of M72.001 peptidyl-Asp metallopetidases is underlined; (4) the three conserved histidines (aa 167, 171, and 177), residues for zinc binding, and glutamate (aa 168), the catalytic residue, are in green; (5) two carbohydrate binding modules of the CBM_4_9 family, aa 302 to aa 432 and aa 461 to aa 586, in blue. (B) The P. aeruginosa predicted PA2783 is homologous to metalloendopeptidases from other bacteria. Interrogation of the non-redundant databases at NCBI (http://www.ncbi.nlm.nih.gov/ webcite; accessed 10/18/2013) was done using BLASTP and the Peptidase Database MEROPS (http://merops.sanger.ac.uk/index.shtml webcite; accessed 10/18/2013) was done using BLAST. Identical aa are shown in red, similar aa in blue, and non-similar aa in black. PA2783 is homologous to the Pseudomonas mendocina ymp (Pmendo) carbohydrate-binding CenC domain-containing protein and the Ni,Fe-hydrogenase I small subunit of Hahella chejuensis KCTC 2396 (Hcheju) across the entire endopeptidase domain. Other proteins contain the HEXXHXXGXXH motif only (highlighted by a yellow box). Amacle, Alteromonas macleodii; Ahydro, Aeromonas hydrophila; Vchole, Vibrio cholerae; Vmimic, V. mimicus; Vvulni, V. vulnificus; Xfraga, Xanthomonas fragariae; Xcampe, X. campestris; Xvesic, X. vesicatoria. Percentages of aa identity and similarity may be found in Additional file 2.
Balyimez et al. BMC Microbiology 2013 13:269 doi:10.1186/1471-2180-13-269