NmPin from the marine thaumarchaeote Nitrosopumilus maritimus is an active membrane associated prolyl isomerase.

Background: Peptidyl-prolyl isomerases (PPIases) are present in all forms of life and play a crucial role in protein folding and regulation. They catalyze the cis-trans isomerization of the peptide bond that precedes proline residues in numerous proteins. The parvulins, which is one family of PPIases, have been extensively investigated in several eukaryotes.