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Structural Biology & Bio-Informatics Division

Dr. Saumen Datta

Senior Scientist
PhD, Indian Institute of Science, Bangalore, India.
Postdoctoral associate, University of Connecticut, Connecticut, USA., 1998-1999
Postdoctoral associate, Washington University in St. Louis, Missouri, USA., 1999-2002
Assistant Research Scientist, John Hopkins University, Maryland, USA., 2002-2004
Quick Hire Fellow, Central Leather Research Institute, 2004-2006
Senior Research Fellow, University of Limerick, 2008

Contact - saumen_datta@iicb.res.in / saumen_datta@hotmail.com

Current Research Interest

Structural and functional investigations of important biological systems by X-ray diffraction methods and some other biophysical techniques.

Current Research topic : Type III Secretion Systems

Several Gram-negative pathogenic bacteria utilize a complex protein delivery system termed as Type III Secretion System (TTSS) to inject virulent proteins directly into the host cells. TTSS has been identified in many animal pathogens – Salmonella spp., Yersinia spp., Shigella spp., Escherichia and Pseudomonas aeruginosa, and plant pathogens - Pseudomonas, Erwinia, Xanthomonas, Ralstonia, Pantoea, etc. Genes involving TTSS are found localized within a particular region of bacterial chromosome or plasmid and encodes (a) proteins for complex macromolecular machine or injectisomes, (b) proteins for translocator and pore formation, (c) virulent effector proteins, (d) three classes of chaperones and (e) other accessory/regulatory proteins.
TTSS injectisome is a proteinaceous machine reconstituted with approximately 20 well conserved proteins. It has two parts, one is bulge shaped lower portion remain anchored into the bacterial cell walls and the other one, needle shaped, constituted with singular protein, protruded out from the cell wall. Upon contact with the host cell translocatory proteins, which remain cytosolic with the help of their dedicated chaperone, secreted out through the needle to form the translocon on the tip of the needle. Concerted effort mainly by three traslocon forming proteins makes the tip of the needle as well as a pore through the host cell membrane. A channel is formed between the bacteria and host cytosol. Bacteria then started injecting virulent proteins through this channel to the host cell and take control of the host’s important cell signaling processes.
            For the last few years we are involved in X-ray crystallographic research on protein, protein complexes from TTSS of Pseudomonas aeruginosa and Yersinia enterocolitica.

Proposed Research topic : Bacterial Collagenases 

Collagenase, a zinc metalloproteinase, catalyzes the hydrolysis of native collagens. More information is available for the large family of mammalian collagenase. Approximately 28 human matrix metalloproteinases (MMPs) with four of their endogenous tissue inhibitors (TIMPs) act together to control the focal proteolysis of extracellular matrix. When unchecked, they can cause arthritis, promote tumor invasion and many others. In the neurons of the adult brain several collagenase/inhibitor systems are expressed and are responsive to changes in neuronal activity. A plethora of mammalian MMP structures, most of them are collagenase, are now available and reveal distinct morphologies and pathologies. However, there is very little known about the structure and catalytic activity of collagenase from microorganisms. My laboratory thus aims to do structural characterization of bacterial collagenases. Bacterial collagenases are being used widely from clinical therapy like wound healing, retainment of placenta, gene therapy to industry like food and leather.

Research positions : Qualified NET/CSIR fellows can directly contact for availability or send their CV by email to me.

Names of the group members including regular staff with designation and research fellows:
Fellow/RA Staff
  1. Supratim Dey, Honorary, E Mail : supu_dey@rediffmail.com
  2. Abhishek Basu, SRF, E Mail : abasu4@rediffmail.com
  3. Atanu Das, JRF, E Mail : atanu.das@hotmail.com
  4. Rakesh Chatterjee, JRF,E Mail : rakesh_rs@iicb.res.in
  5. Dr. Urmisha Das, RA,E Mail : urmishadas@gmail.com

List of important Publications:

  1. Basu A, Chatterjee R, Datta S. Expression, Purification, Structural and Functional Analysis of SycB: A Type Three Secretion Chaperone From Yersinia enterocolitica. Protein J. 2012 Jan;31(1):93-107.
  2. Chen ZW, Datta S, Dubois JL, Klinman JP, Mathews FS. Mutation at a strictly conserved, active site tyrosine in the copper amine oxidase leads to uncontrolled oxygenase activity. Biochemistry. 2010 Aug 31;49(34):7393-402.
  3. Larkin C, Datta S, Harley MJ, Anderson BJ, Ebie A, Hargreaves V, Schildbach JF. Inter- and intramolecular determinants of the specificity of single-stranded  DNA binding and cleavage by the F factor relaxase. Structure. 2005 Oct;13(10):1533-44.
  4. Aravinda S, Datta S, Shamala N, Balaram P. Hydrogen-bond lengths in polypeptide helices: no evidence for short hydrogen bonds. Angew Chem Int Ed Engl. 2004 Dec 10;43(48):6728-31.
  5. Datta S, Rathore RN, Vijayalakshmi S, Vasudev PG, Rao RB, Balaram P, Shamala N. Peptide helices with pendant cycloalkane rings. Characterization of conformations of 1-aminocyclooctane-1-carboxylic acid (Ac8c) residues in peptides. J Pept Sci. 2004 Mar;10(3):160-72.
  6. Datta S, Larkin C, Schildbach JF. Structural insights into single-stranded DNA binding and cleavage by F factor TraI. Structure. 2003 Nov;11(11):1369-79.
  7. Datta S, Ikeda T, Kano K, Mathews FS. Structure of the phenylhydrazine adduct  of the quinohemoprotein amine dehydrogenase from Paracoccus denitrificans at 1.7 A resolution. Acta Crystallogr D Biol Crystallogr. 2003 Sep;59(Pt 9):1551-6.
  8. Larkin C, Datta S, Nezami A, Dohm JA, Schildbach JF. Crystallization and preliminary X-ray characterization of the relaxase domain of F factor TraI. Acta Crystallogr D Biol Crystallogr. 2003 Aug;59(Pt 8):1514-6.
  9. Datta S, Mori Y, Takagi K, Kawaguchi K, Chen ZW, Okajima T, Kuroda S, Ikeda T, Kano K, Tanizawa K, Mathews FS. Structure of a quinohemoprotein amine dehydrogenase with an uncommon redox cofactor and highly unusual crosslinking.  Proc Natl Acad Sci U S A. 2001 Dec 4;98(25):14268-73.
  10. Datta S, Uma MV, Shamala N, Balaram P. Stereochemistry of Schellman Motifs in Peptides. Crystal Structure of a Hexapeptide with a C-terminus 6®1 Hydrogen Bond.   Biopolymers 1999 50; 13-22.
  11. Datta S, Shamala N, Banerjee A, Balaram P. Hydrogen bonding in peptide helices. Analysis of two independent helices in the crystal structure of a peptide Boc-Val-Ala-Leu-Aib-Val-Ala-Phe-OMe. J Pept Res. 1997 Jun;49(6):604-11.
  12. Datta S, Shamala N, Banerjee A, Balaram P. Conformational Variability of Gly-Gly Segments in Peptides. A Comparison of the Crystal Structures of an Acyclic Pentapeptide and an Octapeptide. Bioplolymers 1997: 41; 331-336.
  13. Datta S, Kaul R, Rao RB, Shamala N, Balaram P. Stereochemistry of Linking Segments in the Design of Helix-Helix Motifs in Peptides: Crystallographic Comparison of a Glycyl-Dipropyl-Glycyl Segment in a Tripeptide and in a 14 residue peptide.  J. Chem. Soc., Perkin Trans. 1997: 2; 1659-1664.
  14. Datta S, Shamala N, Banerjee A, Pramanik A, Bhattacharya S, Balaram P. Characterization of Helix Terminating Schellman Motifs in Peptides. Crystal Structure and Nuclear Overhausser Effect Analysis of a Synthetic Heptapeptide Helix.  J. Am. Chem. Soc. 1997, 119; 9246-9251.
  15. Banerjee A, Datta S, Pramanik A, Shamala N, Balaram P. Heterogeneity and Stability of Helical Conformation in Peptides: Crystallographic and NMR studies of a Model Heptapeptide.  J. Am. Chem. Soc. 1996, 118; 9477-9483.
  16. Datta S, Shamala N, Gurunath R, Balaram P. Observation of a mixed antiparallel and parallel beta-sheet motif in the crystal structure of Boc-Ala-Ile-Aib-OMe. Int J Pept Protein Res. 1996 Sep;48(3):209-14.


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