TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*2.A.97.1.1









The leucine zipper-EF band transmembrane protein 1, LetM1.  Reduces mitochondrial Ca2+ uptake in response to cytoplasmic Ca2+entry in pancreatic beta cells (Alam et al. 2012).  LetM1 is a cation/Ca2+ transporter, with apparent affinities of cations in the order Ca2+ = Mn2+ > Gd3+ = La3+ > Sr2+ >> Ba2+, Mg2+, K+, Na+ (Shao et al. 2016). The LetM1 turnover rate is only 2 Ca2+/sec with a Km of ~ 25 microM. LetM1 mediates electroneutral 1 Ca2+/2 H+ antiport (Tsai et al. 2013).  However, NCLX (2.A.19.4.4), rather than LetM1, may mediate miltochondrial Ca2+ extrusion (De Marchi et al. 2014).  Letm1 is associated with seizure attacks in Wolf-Hirschhorn syndrome, and its inhibition and mitochondrial dysfunctions contribute to the development of epileptic seizures. An appropriate LetM1 level may be critical for maintaining normal neuronal functions (Zhang et al. 2014).  Glu221 in the mouse orthologue is essential. The protein is a hexamer with a central cavity and exhibits two different conformational states (Shao et al. 2016).

Eukaryota
Metazoa
LetM1 of Homo sapiens (O95202)
*2.A.97.1.2









Mitochondrial distribution and morphology protein Mdm38p (Yol027c)

Eukaryota
Fungi
Mdm38p of Saccharomyces cerevisiae (Q08179)
*2.A.97.1.3









The mitochondrial LetM1 Ca2+/H+ antiporter (Jiang et al., 2009).

Eukaryota
Metazoa
LetM1 of Drosophila melanogaster (P91927)
*2.A.97.1.4









The yeast Mdm38 (LETM1; YLH47) is a homologue of the human LETM1, the candidate gene for seizures in Wolf-Hirchhorn syndrome. They may be K+/H+ antiporters (Zotova et al., 2010).

Eukaryota
Fungi
LETM1 of Saccharomyces cerevisiae (Q06493)