The lysosomal potassium channel TMEM175 adopts a novel tetrameric architecture.

ABSTRACT: TMEM175 is a lysosomal K⁺ channel that is important for maintaining the membrane potential and pH stability in lysosomes. It contains two homologous copies of a six-transmembrane-helix (6-TM) domain, which has no sequence homology to the canonical tetrameric K⁺ channels and lacks the TVGYG selectivity filter motif found in these channels. The prokaryotic TMEM175 channel, which is present in a subset of bacteria and archaea, contains only a single 6-TM domain and functions as a tetramer. Here, we present the crystal structure of a prokaryotic TMEM175 channel from Chamaesiphon minutus, CmTMEM175, the architecture of which represents a completely different fold from that of canonical K⁺ channels. All six transmembrane helices of CmTMEM175 are tightly packed wi

SUBMITTER: Lee C 

PROVIDER: S-EPMC5901963 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature