Mycobacteria are reported to possess multiple copies of GroELs. Mycobacterium tuberculosis encodes two copies of groEL, of which groEL1 is arranged in an operon with groES and is dispensable whereas groEL2 is located separately on the genome and is indispensable. M. tuberculosis GroELs as inefficient chaperones as a consequence of their lower oligomeric status. Yet abundance of GroEL2 by means of enhanced expression or by chemical collocation has been shown to recover in vivo and in vitro function). Therefore, GroEL2 might be a naturally stunted chaperone, which can function as a canonical chaperonin when present in higher concentrations. Its reduced chaperonin activity is likely to arise either out of weakened substrate interactions, out of impaired stability of the functional oligomeric form, or out of potential defects in allostery.