Almost all systems specific for complex carbohydrates (2.7% – 18 total) are primary active transporters, and more than half of the protein and ligand secretion systems are primary active transporters. Nucleic acid precursor transporters fall into several classes and subclasses, with about equal numbers of primary and secondary carriers. Superfamily representation in Sco Examination of the

superfamilies represented in Sco revealed that of the transmembrane proteins, the largest proportion MK5108 of these www.selleckchem.com/products/OSI027.html proteins falls into the ABC Functional Superfamily (39% – 249 proteins), which includes three independently evolving families of integral membrane proteins [28]. The Major Facilitator Superfamily (MFS) of secondary carriers (18% – 114 proteins) is the second most represented superfamily. The next largest superfamily is the APC Superfamily, which includes 6% of the transmembrane porters (32 proteins). The RND and DMT superfamilies (16 and

17 proteins respectively) check details both contain about 3% of the transporters, while the P-ATPase, CDF, and CPA superfamilies each encompass roughly 2%. Additional superfamilies that each encompass approximately 1% of the porters include the VIC, BART, IT, PTS-GFL, and COX Superfamilies (see TCDB for further explanation). Topological analyses of Sco transporters Sco transport proteins were examined according to predicted topology (Figure 3). The topologies of all proteins included in our study are presented in Figure 3a. Except for the 1 transmembrane segment (TMS) proteins (largely ABC-type extracytoplasmic solute receptors with a single N-terminal signal TMS), proteins with even numbers of TMSs outnumber proteins with odd numbers of TMSs, with the 6 and 12 TMS proteins predominating. For the few channel proteins

(Class 1), 2 and 4 TMS proteins are most numerous, but for carriers (Class 2; primarily MFS carriers) and primary active transporters (Class 3; primarily ABC porters), 12 and 6 TMS proteins predominate, respectively. These are equivalent considering that MFS permeases are functionally monomeric while ABC systems are most frequently dimeric. The evolutionary explanations for these topological observations in transporters have been discussed previously [29]. Figure 3 Streptomyces coelicolor transport protein topologies. Transport Protein kinase N1 protein topologies for all proteins a), channels b), secondary carriers c) and primary active transporters d) in Streptomyces coelicolor. Distribution of transport protein genes within the Sco genome Bentley et al. [11] reported that the S. coelicolor genome is divided into three parts: arm1 (~0 – 1.5 Mbp), arm2 (~6.4 – 8.67 Mbp), and the core (~1.5 – 6.4 Mbp). We therefore examined these three segments of the chromosome to see if the transport protein-encoding genes for any of the well represented (sub)families tended to localize to one of these regions.