This family corresponds to the beta subunit of NADP transhydrogenase in prokaryotes, and either the protein N- or C terminal in eukaryotes. The domain is often found in conjunction with Pfam:PF01262. Pyridine nucleotide transhydrogenase catalyses the reduction of NAD+ to NADPH. A complete loss of activity occurs upon mutation of Gly314 in E. coli [1].

1: A mutation at Gly314 of the beta subunit of the Escherichia coli pyridine nucleotide transhydrogenase abolishes activity and affects the NADP(H)-induced conformational change. Ahmad S, Glavas NA, Bragg PD; Eur J Biochem 1992;207:733-739. PMID:1633824