Protein Family Models

This is a family of bacterial and archaeal proteins that catalyses or regulates the conversion of beta-carotene to retinal [1]. Characterisation of BCD proteins shows them to cleave beta-carotene at its central double bond (15,15') to yield two molecules of all-trans-retinal. However, the oxygen atom of retinal originated not from water but from molecular oxygen, suggesting that the enzyme was a beta-carotene 15,15'-dioxygenase, rather than a mono-oxygenase that catalyses the same biochemical reaction [2,3]. [1]. 11092896. brp and blh are required for synthesis of the retinal cofactor of bacteriorhodopsin in Halobacterium salinarum. Peck RF, Echavarri-Erasun C, Johnson EA, Ng WV, Kennedy SP, Hood L, DasSarma S, Krebs MP;. J Biol Chem. 2001;276:5739-5744. [2]. 19366683. In vitro characterization of a recombinant Blh protein from an uncultured marine bacterium as a beta-carotene 15,15'-dioxygenase. Kim YS, Kim NH, Yeom SJ, Kim SW, Oh DK;. J Biol Chem. 2009;284:15781-15793. [3]. 20229064. Retinal production from beta-carotene by beta-carotene 15,15'-dioxygenase from an unculturable marine bacterium. Kim YS, Park CS, Oh DK;. Biotechnol Lett. 2010;32:957-961. (from Pfam)

Date:

2024-10-16

This integral membrane protein family includes Brp (bacterio-opsin related protein) and Blh (Brp-like protein). Bacteriorhodopsin is a light-driven proton pump with a covalently bound retinal cofactor that appears to be derived beta-carotene. Blh has been shown to cleave beta-carotene to product two all-trans retinal molecules. Mammalian enzymes with similar enzymatic function are not multiple membrane spanning proteins and are not homologous.

Date:

2024-05-30