Protein Family Models

This region in the nucleoside transporter proteins are responsible for determining nucleoside specificity in the human CNT1 and CNT2 proteins (e.g Swiss:O00337) [1]. In the FeoB proteins (e.g. Swiss:O25396), which are believed to be Fe2+ transporters, it includes the membrane pore region, so the function of this region is likely to be more general than just nucleoside specificity [2]. This family may represent the pore and gate, with a wide potential range of specificity. Hence its name 'Gate'. [1]. 10455109. Identification of amino acid residues responsible for the pyrimidine and purine nucleoside specificities of human concentrative Na(+) nucleoside cotransporters hCNT1 and hCNT2. Loewen SK, Ng AM, Yao SY, Cass CE, Baldwin SA, Young JD;. J Biol Chem 1999;274:24475-24484. [2]. 12781516. Is the bacterial ferrous iron transporter FeoB a living fossil?. Hantke K;. Trends Microbiol 2003;11:192-195. (from Pfam)

Date:

2024-10-16

This family consists of nucleoside transport proteins. Swiss:Q62773 is a purine-specific Na+-nucleoside cotransporter localised to the bile canalicular membrane [1]. Swiss:Q62674 is a a Na+-dependent nucleoside transporter selective for pyrimidine nucleosides and adenosine it also transports the anti-viral nucleoside analogues AZT and ddC [2]. This alignment covers the C-terminus of this family of transporters. [1]. 7775409. Primary structure and functional expression of a cDNA encoding the bile canalicular, purine-specific Na(+)-nucleoside cotransporter. Che M, Ortiz DF, Arias IM;. J Biol Chem 1995;270:13596-13599. [2]. 8027026. Cloning and functional expression of a complementary DNA encoding a mammalian nucleoside transport protein. Huang QQ, Yao SY, Ritzel MW, Paterson AR, Cass CE, Young JD;. J Biol Chem 1994;269:17757-17760. (from Pfam)

Date:

2024-10-16

This family consists of nucleoside transport proteins. Swiss:Q62773 is a purine-specific Na+-nucleoside cotransporter localised to the bile canalicular membrane [1]. Swiss:Q62674 is a a Na+-dependent nucleoside transporter selective for pyrimidine nucleosides and adenosine it also transports the anti-viral nucleoside analogues AZT and ddC [2]. This alignment covers the N terminus of this family [1]. 7775409. Primary structure and functional expression of a cDNA encoding the bile canalicular, purine-specific Na(+)-nucleoside cotransporter. Che M, Ortiz DF, Arias IM;. J Biol Chem 1995;270:13596-13599. [2]. 8027026. Cloning and functional expression of a complementary DNA encoding a mammalian nucleoside transport protein. Huang QQ, Yao SY, Ritzel MW, Paterson AR, Cass CE, Young JD;. J Biol Chem 1994;269:17757-17760. (from Pfam)

Date:

2024-10-16

NupC/NupG family nucleoside CNT transporter such as nucleoside permease NupC, which transports nucleosides with a high affinity except guanosine and deoxyguanosine

Date:

2024-10-04

Gene:

nupC

Date:

2019-09-13

The Concentrative Nucleoside Transporter (CNT) Family (TC 2.A.41) Members of the CNT family mediate nucleoside uptake. In bacteria they are energized by H+ symport, but in mammals they are energized by Na+ symport. The different transporters exhibit differing specificities for nucleosides. The E. coli NupC permease transports all nucleosides (both ribo- and deoxyribonucleosides) except hypoxanthine and guanine nucleosides. The B. subtilis NupC is specific for pyrimidine nucleosides (cytidine and uridine and the corresponding deoxyribonucleosides). The mammalian permease members of the CNT family also exhibit differing specificities. Thus, rats possess at least two NupC homologues, one specific for both purine and pyrimidine nucleosides and one specific for purine nucleosides. At least three paralogues have been characterized from humans. One human homologue(CNT1) transports pyrimidine nucleosides and adenosine, but deoxyadenosine and guanosine are poor substrates of this permease. Another (CNT2) is selective for purine nucleosides. Alteration of just a few amino acyl residues in TMSs 7 and 8 interconverts their specificities.

Date:

2022-10-11