Coiled-coil-helix-coiled-coil-helix domain containing protein 3, also known as CHCHD3, is required for maintenance of mitochondrial crista integrity and mitochondrial function. This protein may act as a scaffolding protein that stabilizes protein complexes involved in crista architecture and protein import. It has also been shown to function as a transcription factor which binds to the BAG1 promoter and represses BAG1 transcription. Recombinant human CHCHD3 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.