9.B.69 The Putative Cobalt Transporter (CbtAB) Family

The putative cobalt transporter family consists of two proteins, one (CbtA) of about 230 aas with 6 TMSs, and one (CbtB) of about 70 (60-150) residues, with a single putative TMS. CbtB is possibly a periplasmic or membrane anchored Co2+ binding protein. However, some of the larger homologues have the putative TMS at their C-termini. These proteins are encoded in operons that are subject to regulation by vitamin B12 (Rodionov et al., 2003). They are found in α- and γ-proteobacteria. Their functions are not established.

 


 

References:

Rodionov, D.A., A.G. Vitreschak, A.A. Mironov, and M.S. Gelfand. (2003). Comparative genomics of the vitamin B12 metabolism and regulation in prokaryotes. J. Biol. Chem. 278: 41148-41159.
Examples:

TC#NameOrganismal TypeExample
9.B.69.1.1

The putative cobalt transporter CbtAB

Proteobacteria, Mycobacteria

CbtAB of Pseudomonas putida
CbtA (A5W2Y3)
CbtB (A5W2Y4)

 
9.B.69.1.2

CbtAB of 253 and 71 aas, respectively, with 6 TMSs in a 1 + 2 + 3 TMS arrangement and with 1 N-terminal TMS, respectively.

CbtAB of Mycolicibacterium fortuitum