[1] Homologues are found in a variety of Gram-negative and Gram-positive bacteria, yeast, fungi, plants, animals and viruses.
[1] Based on experimental determination of the BI-1 topology, Bultynck et al. proposes that its C-terminal α-helical 20 amino acid peptide catalyzes Ca2+ flux both in vivo and in vitro.
By mutating one of the critical aspartate residues (D213) in the proposed Ca2+-channel pore in full-length BI-1, D213 proved to be essential for BI-1 dependent ER Ca2+-leak.
Chang et al. published crystal structures of a bacterial homolog, YetJ (TC# 1.A.14.2.3) at 1.9 Å resolution and characterized its calcium leak activity.
[3] The generalized reaction catalyzed by TEGT channels is: As of this edit, this article uses content from "1.A.14 The Testis-Enhanced Gene Transfer (TEGT) Family", which is licensed in a way that permits reuse under the Creative Commons Attribution-ShareAlike 3.0 Unported License, but not under the GFDL.