Catalyzes the isomerization of trans-3-nonenoyl-CoA into trans-2-nonenoyl-CoA (PubMed:24344334). May also have activity towards other enoyl-CoA species (Probable). a (3Z)-enoyl-CoA = a 4-saturated (2E)-enoyl-CoA a (3E)-enoyl-CoA = a 4-saturated (2E)-enoyl-CoA (3E)-nonenoyl-CoA = (2E)-nonenoyl-CoA Expressed at high levels in the kidney. Also detected at very low levels in the duodenum, jejunum, ileum, heart, liver, lung, and brown adipose tissue (at protein level). In the kidney, expression seems to be localized mainly to the proximal tubule. The ACB (acyl-CoA-binding) domain is truncated and may be non-functional. Belongs to the enoyl-CoA hydratase/isomerase family.