Identification and characterization of Pseudomonas aeruginosa PA-IIL lectin gene and protein compared to PA-IL

Using the 33 N-terminal amino acids of the fucose/mannose binding: lectin P A-IIL of Pseudomonas aeruginosa ATCC 33347 in a tblastn search of P. aerugi nosa PAO1 genomic sequence in GenBank revealed a single open reading frame encoding a 114-amino acid protein (excluding initiator methionine) perfectl y matching that amino acid sequence. following its stop codon there is a GC -rich sequence having a perfect dyed symmetry promoting formation of a hair pin loop structure, potentially enabling rho-independent transcription term ination. Upstream of the putative ribosomal binding site there are sequenxc es resembling Vibrio fischeri luxI box, consistent with autoinduction of th is gene. The predicted PA-IIL molecular mass, confirmed by mass spectrometr y, is 11 732 Da. Its pI is 3.88. The C-terminal domain is particularly hydr ophobic, implying possible embedding in the cell membrane. PA-IIL is simila r to P, aeruginosa PA-IL lectin in some amino acids and potential glycosyla tion sites but lacks cysteine, methionine and histidine. Despite their rela tions in functions and regulation, their genes are widely separated (by abo ut 867.5 kb). (C) 2000 Federation of European Microbiological Societies. Pu blished by Elsevier Science B.V. All rights reserved.