T-complex protein-1 (TCP1) complex, a chaperonin class of protein, ubiquitous in all genera of life, is involved in intracellular assembly and folding of various proteins. The gamma subunit of TCP1 complex (TCP1 gamma), plays a pivotal role in the folding and assembly of cytoskeleton protein(s) as an individual or complexed with other subunits. Here, we report for the first time cloning, characterization and expression of the TCP1 gamma of Leishmania donovani (LdTCP1 gamma), the causative agent of Indian Kala-azar. Primary sequence analysis of LdTCP1 gamma revealed the presence of all the characteristic features of TCP1 gamma. However, leishmanial TCP1 gamma represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. LdTCP1 gamma exhibited differential expression in different stages of promastigotes. The nondividing stationary phase promastigotes exhibited 2.5-fold less expression of LdTCP1 gamma as compared to rapidly dividing log phase parasites. The sub-cellular distribution of LdTCP1 gamma was studied in log phase promastigotes by employing indirect immunofluorescence microscopy. The protein was present not only in cytoplasm but it was also localized in nucleus, pen-nuclear region, flagella, flagellar pocket and apical region. Co-localization of LdTCP1 gamma with actin suggests that, this gene may have a role in maintaining the structural dynamics of cytoskeleton of parasite. (C) 2012 Elsevier Inc. All rights reserved.