Three dimensional modeling of C-terminal loop of CssA subunit in CS6 of Enterotoxigenic Escherichia coli and its interaction with the 70 KDa domain of Fibronectin



Raghunath Chatterjee1, 3#, Abhisek Ghosal2, 4#, Subrata Sabui2, Nabendu Sekhar Chatterjee2*



1Biomedical Informatics Centers of ICMR, National Institute of Cholera & Enteric Diseases, P33 C.I.T. Road, Scheme XM, Beliaghata, Kolkata 700 010, India; 2Division of Biochemistry, National Institute of Cholera & Enteric Diseases, Kolkata, India; 3Present address: National Cancer Institute, NIH, Bethesda, MD USA 20852; 4Present address: University of California, Irvine, VA Medical Center, 151, 5901 East 7th St, Long Beach, CA 90822; #Authors contributed equally


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Received May 11, 2011; Accepted May 12, 2011; Published July 06, 2011



Colonization factor CS6 of enterotoxigenic Escherichia coli (ETEC) helps to establish the adherence of CS6-expressing ETEC in the intestinal wall. CS6 is composed of two structural subunits, known as CssA and CssB. During CS6-expressing ETEC adherence in intestinal wall, 15 amino acid residues containing C-terminal region of CssA subunit, help to bind with N-terminal 70kDa domain of fibronectin (Fn). In this study, we have predicted a theoretical structural model for C-terminal domain of CssA by homology modelling using protein data bank (PDB) file, 1NTY-A as template (66.67% sequence identity) in Discovery Studio. The structural model of N-terminal region of Fn was also determined by homology modelling using PDB files 1FBR and 1E88 as templates. The structure of the model was also validated by Ramachandran plot. The energy minimization for Fn was performed in standard dynamic cascade using Steepest Descent algorithm followed by Adopted Basis NR algorithm in Discovery studio. The docking model between C-terminal domain and fibronectin were generated by using ClusPro algorithm. This docking study would be help for better understanding how CS6 interacts with fibronectin of intestinal extracellular matrix in the host during infection, and would be of great help towards subunit vaccine generation.



Colonization factor CS6, ETEC, fibronectin, homology modelling, Ramachandran plot, docking model.



Chatterjee et al. Bioinformation 6(8): 307-310 (2011)

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P Kangueane






Biomedical Informatics



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