TCDB is operated by the Saier Lab Bioinformatics Group
« See all members of the family


1.A.1.11.26
Two pore Ca2+ > Na+, Li+ or K+ (non-selective for these three monovalen caions) channel protein of 733 aas and 12 TMSs, TPC1 (Guo et al. 2017). The crystal structure of this vacuolar two-pore channel, a homodimer, has been solved (Guo et al. 2015) (Kintzer and Stroud 2016). Activation requires both voltage and cytosolic Ca2+. Ca2+ binding to the cytosolic EF-hand domain triggers conformational changes coupled to the pair of pore-lining inner helices from the first 6-TMS domains, whereas membrane potential only activates the second voltage-sensing domain, the conformational changes of which are coupled to the pair of inner helices from the second 6-TMS domains. Luminal Ca2+ or Ba2+ modulates voltage activation by stabilizing the second voltage-sensing domain in the resting state and shift voltage activation towards more positive potentials. The basis for understanding ion permeation, channel activation, the location of voltage-sensing domains and regulatory ion-binding sites is partially explained by the 3-d structure (Kintzer and Stroud 2016). Only the second Shaker domain senses voltage (Jaƛlan et al. 2016).

Accession Number:Q94KI8
Protein Name:Two pore calcium channel protein 1
Length:733
Molecular Weight:84873.00
Species:Arabidopsis thaliana (Mouse-ear cress) [3702]
Number of TMSs:12
Location1 / Topology2 / Orientation3: Vacuole membrane1 / Multi-pass membrane protein2
Substrate sodium ions

Cross database links:

Structure:
5E1J   5dqq     

External Searches:

  • Search: DB with
  • BLAST ExPASy (Swiss Institute of Bioinformatics (SIB) BLAST)
  • CDD Search (Conserved Domain Database)
  • Search COGs (Clusters of Orthologous Groups of proteins)
  • 2° Structure (Network Protein Sequence Analysis)

Analyze:

Predict TMSs (Predict number of transmembrane segments)
Window Size: Angle:  
Window Size: Angle:  
FASTA formatted sequence
1:	MEDPLIGRDS LGGGGTDRVR RSEAITHGTP FQKAAALVDL AEDGIGLPVE ILDQSSFGES 
61:	ARYYFIFTRL DLIWSLNYFA LLFLNFFEQP LWCEKNPKPS CKDRDYYYLG ELPYLTNAES 
121:	IIYEVITLAI LLVHTFFPIS YEGSRIFWTS RLNLVKVACV VILFVDVLVD FLYLSPLAFD 
181:	FLPFRIAPYV RVIIFILSIR ELRDTLVLLS GMLGTYLNIL ALWMLFLLFA SWIAFVMFED 
241:	TQQGLTVFTS YGATLYQMFI LFTTSNNPDV WIPAYKSSRW SSVFFVLYVL IGVYFVTNLI 
301:	LAVVYDSFKE QLAKQVSGMD QMKRRMLEKA FGLIDSDKNG EIDKNQCIKL FEQLTNYRTL 
361:	PKISKEEFGL IFDELDDTRD FKINKDEFAD LCQAIALRFQ KEEVPSLFEH FPQIYHSALS 
421:	QQLRAFVRSP NFGYAISFIL IINFIAVVVE TTLDIEESSA QKPWQVAEFV FGWIYVLEMA 
481:	LKIYTYGFEN YWREGANRFD FLVTWVIVIG ETATFITPDE NTFFSNGEWI RYLLLARMLR 
541:	LIRLLMNVQR YRAFIATFIT LIPSLMPYLG TIFCVLCIYC SIGVQVFGGL VNAGNKKLFE 
601:	TELAEDDYLL FNFNDYPNGM VTLFNLLVMG NWQVWMESYK DLTGTWWSIT YFVSFYVITI 
661:	LLLLNLVVAF VLEAFFTELD LEEEEKCQGQ DSQEKRNRRR SAGSKSRSQR VDTLLHHMLG 
721:	DELSKPECST SDT