Sequence analysis of putative N-acetylglucosaminidase, SACOL2666 gene in S. aureus

A novel N-acetylglucosaminidase encoded by SACOL2666 has been isolated from S. aureus SH1000. The nucleotide sequence of the clone designated pQE60-xSCaQ was determined. The gene is 1860 bp in length and contains an open reading frame from 82 to 1860 bp encoding 592 amino acids residues of mature protein with a predicted molecular weight of 66 kD. BLAST analysis of SACOL2666 nucleotide sequence shows 100% identity with muramoyl-L-alanine amidase from S. aureus COL complete genome and 99% identity with N-acetylglucosaminidase protein family from S. aureus ECT-R2. While the deduced amino acids sequence of SACOL2666 shows 99% homology with N-acetylglucosaminidase family protein S. aureus CIG547 at locus name SACIG547_0476 in NCBI database. Multiple alignments show that SACOL2666 has conserved sequence pattern with characterized N-acetylglucosaminidase (overlapping with amidase domain) than bifunctional domain enzymes (in tandem) such as Atl from S. aureus. SACOL2666 has consensus amino acids at carboxylic active sites reported in Auto, a member of Glycoside hydrolase family. Catalytic sites for N-glucosaminidase D and E were found in SACOL2666 at E352, E386 and D452. Phylogenetic analysis of amino acid sequence from the selected N-acetylglucosaminidase indicated close phylogenetic relationship of SACOL2666 with AcmB than Atl.