Bioinformatic Comparison of Bacterial Secretomes

Catharine Song, Aseem Kumar, Mazen Saleh
2009 Genomics, Proteomics & Bioinformatics  
The rapid increasing number of completed bacterial genomes provides a good opportunity to compare their proteomes. This study was undertaken to specif ically compare and contrast their secretomes-the fraction of the proteome with predicted N-terminal signal sequences, both type I and type II. A total of 176 theoretical bacterial proteomes were examined using the ExProt program. Compared with the Gram-positives, the Gram-negative bacteria were found, on average, to contain a larger number of
more » ... ntial Sec-dependent sequences. In the Gram-negative bacteria but not in the others, there was a positive correlation between proteome size and secretome size, while there was no correlation between secretome size and pathogenicity. Within the Gram-negative bacteria, intracellular pathogens were found to have the smallest secretomes. However, the secretomes of certain bacteria did not f it into the observed pattern. Specif ically, the secretome of Borrelia burgdoferi has an unusually large number of putative lipoproteins, and the signal peptides of mycoplasmas show closer sequence similarity to those of the Gramnegative bacteria. Our analysis also suggests that even for a theoretical minimal genome of 300 open reading frames, a fraction of this gene pool (up to a maximum of 20%) may code for proteins with Sec-dependent signal sequences.
doi:10.1016/s1672-0229(08)60031-5 pmid:19591790 pmcid:PMC5054224 fatcat:uipdzofbgzaetal7xtixrxkwxe