PROGRESS WITH GENE-PRODUCT MAPPING OF THE MOLLICUTES - MYCOPLASMA-GENITALIUM

A protein map of the smallest known self-replicating organism, Mycopla sma genitalium (Class: Mollicutes), revealed a high proportion of acid ic proteins. Amino acid composition was used to putatively identify, o r provide unique parameters, for 50 gene products separated by two-dim ensional gel electrophoresis. A further 19 proteins were subjected to peptide-mass fingerprinting using matrix-assisted laser desorption ion isation-time of flight (MALDI-TOF) mass spectrometry and 4 were subjec ted to N-terminal Edman degradation. The majority of M. genitalium pro teins remain uncharacterised. However, the combined approach of amino acid analysis and peptide-mass fingerprinting allowed gene products to be linked to homologous genes in a variety of organisms. This has all owed proteins to be identified prior to detection of their respective genes via the M. genitalium sequencing initiative. The principle of 'h ierarchical' analysis for the mass screening of proteins and the analy sis of microbial genomes via their protein complement or 'proteome' is detailed. Here, characterisation of gene products depends upon the qu ickest and most economical technologies being employed initially, so a s to determine if a large number of proteins are already present in bo th homologous and heterologous species databases. initial screening, w hich lends itself to automation and robotics, can then be followed by more time and cost intensive procedures, when necessary.