Isolation and characterization of a main porin from the outer membrane of Salinibacter ruber.
J Bioenerg Biomembr
; 54(5-6): 273-281, 2022 12.
Article
in En
| MEDLINE
| ID: mdl-36229623
ABSTRACT
Salinibacter ruber is an extremophilic bacterium able to grow in high-salts environments, such as saltern crystallizer ponds. This halophilic bacterium is red-pigmented due to the production of several carotenoids and their derivatives. Two of these pigment molecules, salinixanthin and retinal, are reported to be essential cofactors of the xanthorhodopsin, a light-driven proton pump unique to this bacterium. Here, we isolate and characterize an outer membrane porin-like protein that retains salinixanthin. The characterization by mass spectrometry identified an unknown protein whose structure, predicted by AlphaFold, consists of a 8 strands beta-barrel transmembrane organization typical of porins. The protein is found to be part of a functional network clearly involved in the outer membrane trafficking. Cryo-EM micrographs showed the shape and dimensions of a particle comparable with the ones of the predicted structure. Functional implications, with respect to the high representativity of this protein in the outer membrane fraction, are discussed considering its possible role in primary functions such as the nutrients uptake and the homeostatic balance. Finally, also a possible involvement in balancing the charge perturbation associated with the xanthorhodopsin and ATP synthase activities is considered.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Porins
/
Bacteroidetes
Language:
En
Journal:
J Bioenerg Biomembr
Year:
2022
Document type:
Article
Affiliation country:
Suecia