Protein Family Models

Members of this family, including Csac_0668 from Caldicellulosiruptor saccharolyticus, are homologous to the N-terminal half of the copper chaperone CopZ from Archaeoglobus fulgidus. While the C-terminal half of CopZ resembles other previously known copper-binding domain, and binds a copper atom, the N-terminus was found to bind an additional copper and a 2Fe-2S iron-sulfur cluster. Members of the family described here contain an additional 20 amino acids N-terminal to region that aligns to CopZ, containing multiple Cys residues (sometimes four in a row) or selenocysteine in a suggested metal-binding CU motif. The proposed function for members of this family is as a metallochaperone. Note that some homologs outside the scope of this family, such as WP_240162626.1, similarly are selenoproteins but have the selenocysteine at different site.

Date:

2024-04-11

This is N-terminal domain containing a mononuclear metal center for zinc binding found in copper chaperone CopZ proteins [1]. [1]. 17609202. Characterization and structure of a Zn2+ and [2Fe-2S]-containing. copper chaperone from Archaeoglobus fulgidus.. Sazinsky MH, LeMoine B, Orofino M, Davydov R, Bencze KZ,. Stemmler TL, Hoffman BM, Arguello JM, Rosenzweig AC;. J Biol Chem. 2007;282:25950-25959. (from Pfam)

Date:

2024-04-03

The two Fe ions are each coordinated by two conserved cysteine residues. This domain occurs alone in small proteins such as Bacterioferritin-associated ferredoxin (BFD, Swiss:P13655). The function of BFD is not known, but it may may be a general redox and/or regulatory component involved in the iron storage or mobilisation functions of bacterioferritin in bacteria [1]. This domain is also found in nitrate reductase proteins in association with Nitrite and sulphite reductase 4Fe-4S domain [2] (Pfam:PF01077), Nitrite/Sulfite reductase ferredoxin-like half domain (Pfam:PF03460) and Pyridine nucleotide-disulphide oxidoreductase (Pfam:PF00070). It is also found in NifU nitrogen fixation proteins, in association with NifU-like N terminal domain (Pfam:PF01592) and NifU-like domain [3] (Pfam:PF01106). [1]. 8639572. A [2Fe-2S] protein encoded by an open reading frame upstream of. the Escherichia coli bacterioferritin gene.. Garg RP, Vargo CJ, Cui X, Kurtz DM Jr;. Biochemistry 1996;35:6297-6301.. [2]. 8954950. Spectroscopic and voltammetric characterisation of the. bacterioferritin-associated ferredoxin of Escherichia coli.. Quail MA, Jordan P, Grogan JM, Butt JN, Lutz M, Thomson AJ,. Andrews SC, Guest JR;. Biochem Biophys Res Commun 1996;229:635-642.. [3]. 9889981. Iron storage in bacteria.. Andrews SC;. Adv Microb Physiol 1998;40:281-351. (from Pfam)

Date:

2024-04-03