Family based on orphan protein (TM0875) from Thermotoga maritima that has been structurally determined as PDB:1022. The TM0875 gene of Thermotoga maritima encodes a hypothetical protein NP_228683 [1] of unknown function. Analysis of TM0875 genomic context reveals the presence of MMT1 (a predicted Co/Zn/Cd cation transporter) and an inactive homolog of metal-dependent proteases. 1O22 shows weak structural similarity with the phosphoribosylformylglycinamidine synthase 1t4a (Dali Z-scr=4.6), the yggU protein (PDB structure:1n91; with DALI Z-scr=3), and with the thioesterase superfamily member (PDB structure 2cy9 - found using FATCAT), even though they have very low sequence identity.

1: Crystal structure of an orphan protein (TM0875) from Thermotoga maritima at 2.00-A resolution reveals a new fold. Bakolitsa C, Schwarzenbacher R, McMullan D, Brinen LS, Canaves JM, Dai X, Deacon AM, Elsliger MA, Eshagi S, Floyd R,\t Godzik A, Grittini C, Grzechnik SK, Jaroszewski L, Karlak C, Klock HE, Koesema E, Kovarik JS, Kreusch A, Kuhn P, Lesley SA, McPhillips TM, Miller MD, Morse A, Moy K, Ouyang J, Page R, Quijano K, Robb A, Spraggon G, Stevens RC, van den Bedem H, Velasquez J, Vincent J, von Delft F, Wang X, West B, Wolf G, Hodgson KO, Wooley J, Wilson IA. Proteins. 2004 Aug 15;56(3):607-10. PMID:15229892