This is the C-terminal domain found in rubredoxin reductase (RdxR) present in Pseudomonas aeruginosa. RdxR are important in prokaryotes as they allow for the metabolism of inert n-alkanes and RdxR is also crucial for archaea and anaerobic bacteria in the response to oxidative stress. This domain is known to recognise and bind to rubredoxin [1].

1: Crystal structure of the electron transfer complex rubredoxin rubredoxin reductase of Pseudomonas aeruginosa. Hagelueken G, Wiehlmann L, Adams TM, Kolmar H, Heinz DW, Tummler B, Schubert WD; Proc Natl Acad Sci U S A. 2007;104:12276-12281. PMID:17636129