This family consists of several selenium binding proteins from eukaryotes, bacteria and archaea. It is thought that SP56 participates in late stages of intra-Golgi protein transport [1]. The Lotus japonicus homologue of SBP56, LjSBP, is thought to have more than one physiological role and can be implicated in controlling the oxidation/reduction status of target proteins, in vesicular Golgi transport [2]. Human selenium-binding protein 1 (SELENBP1) is a methanethiol oxidase (MTO) that converts methanethiol to H2O2, formaldehyde, and H2S [3].

1: A 56-kDa selenium-binding protein participates in intra-Golgi protein transport. Porat A, Sagiv Y, Elazar Z; J Biol Chem 2000;275:14457-14465. PMID:10799528

2: Lotus japonicus gene Ljsbp is highly conserved among plants and animals and encodes a homologue to the mammalian selenium-binding proteins. Flemetakis E, Agalou A, Kavroulakis N, Dimou M, Martsikovskaya A, Slater A, Spaink HP, Roussis A, Katinakis P; Mol Plant Microbe Interact 2002;15:313-322. PMID:12026169

3: Mutations in SELENBP1, encoding a novel human methanethiol oxidase, cause extraoral halitosis. Pol A, Renkema GH, Tangerman A, Winkel EG, Engelke UF, de Brouwer APM, Lloyd KC, Araiza RS, van den Heuvel L, Omran H, Olbrich H, Oude Elberink M, Gilissen C, Rodenburg RJ, Sass JO, Schwab KO, Schafer H, Venselaar H, Sequeira JS, Op den Camp HJM, Wevers RA; Nat Genet. 2018;50:120-129. PMID:29255262