A novel molecular chaperone GroEL2 from Rhodococcus ruber and its fusion chimera with nitrile hydratase for co-enhanced activity and stability

•Novel R. ruber chaperones were identified by transcriptome analysis.•R. ruber chaperone GroEL2 was distinguished from conventional GroEL.•GroEL2 showed high self-thermal stability and protection effect on other proteins.•NHase-GroEL2 fusion chimera enhanced the activity of NHase by 63.6%.•It also enhanced thermal stability by 2.9× and acrylamide resistance by 1.1×.