ABSTRACT
We developed novel programs for displaying and analyzing the transmembrane alpha-helical segments (TMSs) in the aligned sequences of homologous integral membrane proteins. TMS_ALIGN predicts the positions of putative TMSs in multiply aligned protein sequences and graphically shows the TMSs in the alignment. TMS_SPLIT (1). predicts the positions of TMSs for each sequence; (2). allows a user to select proteins with a specified number of TMSs, and (3). splits the sequences into groups of TMSs of equal numbers. TMS_CUT works like TMS_SPLIT, but it can cut sequences with any combination of TMSs. The BASS program similarly allows comparison of protein repeat elements, equivalent to TMS_SPLIT plus IC, but it provides the comparison data expressed in BLAST E values. These programs, together with the IntraCompare program, facilitate the identification of repeat sequences in integral membrane proteins. They also facilitate the estimation of protein topology and the determination of evolutionary pathways.
Subject(s)
Internet , Membrane Proteins/chemistry , Sequence Alignment , Sequence Homology, Amino Acid , Software , Amino Acid Sequence , Computational Biology , Membrane Proteins/genetics , Molecular Sequence DataABSTRACT
We here describe all recognized established and putative transport proteins encoded within the genome of Bacillus subtilis. These fall into four classes of established transporter types: (1) channel proteins, (2) secondary active transporters, (3) primary active transporters, and (4) group translocators of the sugar-transporting phosphotransferase system (PTS). Additionally, some transporters are recognized that utilize an unknown mode of action or energy coupling mechanism. The secondary carriers (which represent the majority of Bacillus transporters) are subdivided according to substrate specificity and family association. Characteristics of the families as well as the individual transport systems are presented when sufficient information is available. The recognized transporters fall into 58 families including 4 channel types, 42 secondary carrier types, 3 primary carrier types, 4 PTS-types and 5 unknown types.
