Functional insights by comparison of modeled structures of 18kDa small heat shock protein and its mutant in Mycobacterium leprae



Elengikal Abdul Azeez Rehna1, Sanjeev Kumar Singh2,* and Kuppamuthu Dharmalingam1




1Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai-625021, Tamil Nadu, India; 2Centre of Excellence in Bioinformatics, School of Biotechnology, Madurai Kamaraj University, Madurai-625021, Tamil Nadu, India

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received August 20, 2008; revised November 11, 2008; accepted December 16, 2008; published December 31, 2008


In this work we are proposing Homology modeled structures of Mycobacterium leprae 18kDa heat shock protein and its mutant. The more closely related structure of the small heat shock protein (sHSP) belonging to the eukaryotic species from wheat sHSP16.9 and 16.3kDa ACR1 protein from Mycobacterium tuberculosis were used as template structures. Each model contains an N-terminal domain, alpha-crystalline domain and a C-terminal tail. The models showed that a single point mutation from serine to proline at 52nd position causes structural changes. The structural changes are observed in N-terminal region and alpha-crystalline domains. Serine in 52nd position is observed in β4 strand and Proline in 52nd position is observed in loop. The number of residues contributing α helix at N-terminal region varies in both models. In 18S more number of residues is present in α helix when compared to 18P. The loop regions between β3 and β4 strands of both models vary in number of residues present in it. Number of residues contributing β4 strand in both models vary. β6 strand is absent in both models. Major functional peptide region of alpha crystalline domains of both models varies. These differences observed in secondary structures support their distinct functional roles. It also emphasizes that a point mutation can cause structural variation.



Mycobacterium leprae; Mycobacterium tuberculosis; heat shock protein; homology modeling


Rehna et al., Bioinformation 3(5): 230-234 (2008)

Edited by

P. Kangueane




Biomedical Informatics




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