A heterodimeric enzyme complex composed of subunits leuC and leuD. Catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate, via the formation of 2-isopropylmaleate. [ https://biocyc.org/META/NEW-IMAGE?type=NIL&object=3-ISOPROPYLMALISOM-CPLX GOC:jl http://www.ncbi.nlm.nih.gov/pubmed/7026530 ]
Synonyms: isopropylmalate isomerase complex