Wednesday 16 November 2005

BADASP: predicting functional specificity in protein families using ancestral sequences

Edwards RJ & Shields DC (2005): BADASP: predicting functional specificity in protein families using ancestral sequences. Bioinformatics 21(22):4190-1.

Abstract

SUMMARY: Burst After Duplication with Ancestral Sequence Predictions (BADASP) is a software package for identifying sites that may confer subfamily-specific biological functions in protein families following functional divergence of duplicated proteins. A given protein phylogeny is grouped into subfamilies based on orthology/paralogy relationships and/or user definitions. Ancestral sequences are then predicted from the sequence alignment and the functional specificity is calculated using variants of the Burst After Duplication method, which tests for radical amino acid substitutions following gene duplications that are subsequently conserved. Statistics are output along with subfamily groupings and ancestral sequences for an easy analysis with other packages.

AVAILABILITY: BADASP is freely available from http://www.bioinformatics.rcsi.ie/~redwards/badasp/

PMID: 16159912

Wednesday 2 November 2005

Correlation of probiotic Lactobacillus salivarius growth phase with its cell wall-associated proteome

Kelly P, Maguire PB, Bennett M, Fitzgerald DJ, Edwards RJ, Thiede B, Treumann A, Collins JK, O’Sullivan GC, Shanahan F & Dunne C (2005): Correlation of probiotic Lactobacillus salivarius growth phase with its cell wall-associated proteome. FEMS Microbiol. Lett. 252(1):153-159.

Abstract

Lactobacillus salivarius subsp. salivarius UCC118 is a probiotic bacterium that was originally isolated from human intestinal tissues and was subsequently shown in a pilot study to alleviate symptoms associated with mild-moderate Crohn’s disease. Strain UCC118 can adhere to animal and human intestinal tissue, and to both healthy and inflamed ulcerative colitis mucosa, irrespective of location in the gut. In this study, an enzymatic technique has been combined with proteomic analysis to correlate bacterial growth phase with the presence of factors present in the cell wall of the bacterium. Using PAGE electrophoresis, it was determined that progression from lag to log to stationary growth phases in vitro correlated with increasing prominence of an 84kD protein associated with in vitro adherence ability. Isolated proteins from the 84kD band region were further separated by two-dimensional electrophoresis, resolving this band into 20 individual protein spots at differing isoelectric points. The protein moieties were excised, trypsin digested and subjected to tandem mass spectrometry. The observed proteins are analogous to those reported to be associated with the Listeria monocytogenes cell-wall proteome, and include DnaK, Ef-Ts and pyruvate kinase. These data suggest that at least some of the beneficial attributes of probiotic lactobacilli, and in particular this strain, may be due to nonpathogenic mimicry of pathogens and potentially be mediated through a form of attenuated virulence.

PMID: 16214296