Proportion of membrane proteins in proteomes of 15 single-cell organisms analyzed by the SOSUI prediction system.
A software system, SOSUI, was previously developed for discriminating between soluble and membrane proteins and predicting transmembrane regions (Hirokawa et al., Bioinformatics, 14 (1998) 378-379). The performance of the system was 99% for the discrimination between two types of proteins and 96% for the prediction of transmembrane helices. When all of the amino acid sequences from 15 single-cell organisms were analyzed by SOSUI, the proportion of predicted polytopic membrane proteins showed an almost constant value of 15-20%, irrespective of the total genome size. However, single-cell organisms appeared to be categorized in terms of the preference of the number of transmembrane segments: species with small genomes were characterized by a significant peak at a helix number of approximately six or seven; species with large genomes showed a peak at 10 or 11 helices; and species with intermediate genome sizes showed a monotonous decrease of the population of membrane proteins against the number of transmembrane helices.
Mitaku
S
S
Tokyo University of Agriculture and Technology, Department of Biotechnology, Japan.
Ono
M
M
Hirokawa
T
T
Boon-Chieng
S
S
Sonoyama
M
M
D001105:Archaea / Q000378:metabolism*; D001185:Artificial Intelligence; D001419:Bacteria / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D016366:Open Reading Frames; D020543:Proteome / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012984:Software
D008565:Membrane Proteins; D020543:Proteome