Main Menu

Dr. Karthikeyan Subramanian
Protein Crystallography

Contact Address:

Institute of Microbial Technology,
Sector 39-A, Chandigarh – 160 036, India
Phone: +91-172-6665193
Fax: +91-172-2690585

Write-up of research and development interests/focus, past and present goals:

Research Interests:

Our lab is interested in determining the three-dimensional structure of macromolecules by X-ray Crystallography. In addition, we employ other biophysical and biochemical techniques to understand the structure-function relationship and molecular mechanism of important proteins. Proteins of our interest are divided into three categories:

  • Proteins that is essential for survival and growth of bacteria, fungi, yeast and other microbial organisms. Three dimensional structures of these proteins will be determined by X-ray crystallography and subsequently used as a model for designing drugs, specific to the target as well as for the pathogenesis.

  • Molecular characterization, structure-function relationship of enzymes that is useful for industrial purpose. The structure determination of this protein will be helpful to improve the stability of the enzymes by mutational studies and thus modulate the function of these important enzymes.

  • Identification and characterization of proteins with a novel fold. Structure determination of proteins with novel fold may shed light on the unknown/unexplored function of that protein family.

Selected list of Publications and Patents:


* ChaC2: An Enzyme for Slow Turnover of Cytosolic Glutathione Amandeep Kaur, Ruchi Gautam, Ritika
Srivastava, Avinash Chandel, Akhilesh Kumar, Subramanian Karthikeyan* and Anand Kumar Bachhawat*.
Journal of Biological Chemistry. (2017), 292, 638-651. doi: 10.1074/jbc.M116.727479.

* Molecular dynamics studies unravel role of conserved residues responsible for movement of ions
into active site of DHBPS. Ranajit Nivrutti Shinde, Subramanian Karthikeyan* & Balvinder Singh*.
Sci Rep. (2017), 7:40452, 1-8. doi: 10.1038/srep40452.


* Biochemical and structural characterization of a novel halotolerant cellulase from soil metagenome. Roma
Garg, Ritika Srivastava, Vijaya Brahma, Lata Verma, Subramanian Karthikeyan* & Girish Sahni*.
Sci Rep. (2016), 6:39634, 1-15. doi: 10.1038/srep39634.

* Structural and biochemical characterization of GTP cyclohydrolase II from Helicobacter pylori reveals its redox dependent catalytic activity. Savita Yadav and Subramanian Karthikeyan*. Journal of Structural Biology. (2015), 192, 100-115


* Structural Basis for Competitive Inhibition of 3,4-Dihydroxy-2-butanone-4-phosphate Synthase from Vibrio cholera. Zeyaul Islam, Adarsh Kumar, Suruchi Singh, Laurent Salmon and Subramanian Karthikeyan*. Journal of Biological Chemistry. (2015), 290, 11293-11308. doi:10.1074/jbc.M114.611830.


 * Evidence that phosphorylation of threonine in GT motif triggers activation of PknA, a eukaryotic-type Serine/Threonine kinase from Mycobacterium tuberculosis. Sandeep K Ravala, Suruchi Singh, Ghanshyam S Yadav, Sanjay Kumar, Subramanian Karthikeyan*, Pradip K. Chakraborti*. FEBS J. (2015), 282(8), 1419-1431. doi:10.1111/febs.13230.


 * Identification of crucial amino acids of bacterial peptide deformylases affecting enzymatic activity in response to oxidative stress. Kumar S, Kanudia P, Karthikeyan S, Chakraborti PK. J Bacteriol. (2014) 196, 90-99.


* The crystal structure reveals the molecular mechanism of bifunctional 3,4-dihydroxy-2-butanone 4-phosphate synthase/GTP cyclohydrolase II (Rv1415) from Mycobacterium tuberculosis Mirage Singh, Pankaj Kumar, Savita Yadav, Ruchi Gautam, Nidhi Sharma and Subramanian Karthikeyan*. Acta Cryst (2013) D69, 1633-1644.


* Insufficient (Sub-native) Helix Content in Soluble/ Solid Aggregates of Recombinant and Engineered Forms of IL-2 Throws Light on How Aggregated IL-2 is Biologically Active. Uzma Fatima, Balvinder Singh, Karthikeyan Subramanian, Purnananda Guptasarma. Protein J. (2012), 31:529–543.


* Structures of ternary complexes of aspartate semialdehyde dehydrogenase (Rv3708c) from Mycobacterium tuberculosis H37Rv. Rajan Vyas, Rupinder Tewari, Manfred S. Weiss and Subramanian Karthikeyan*. Acta. Cryst. (2012). D68, 671-679


* Amino acids involved in polyphosphate synthesis and its mobilization are distinct in polyphosphate kinase-1 from Mycobacterium tuberculosis. Payal Mittal, Subramanian Karthikeyan, Pradip K. Chakraborti*. PLoS one (2011). 6(11), e27398.


* Structural basis for pH dependent monomer-dimer transition of 3, 4-dihydroxy 2-butanone-4-phosphate synthase domain from M. tuberculosis. Mirage Singh, Pankaj Kumar and Subramanian Karthikeyan*. Journal of Structural Biology. (2011), 174, 374–384.

* Crystal structure analysis of icosahedral lumazine synthase from Salmonella typhimurium, an antibacterial drug target. Pankaj Kumar, Mirage Singh and Subramanian Karthikeyan*. Acta Cryst. (2011), D67, 131-139.


* Potential anti-bacterial drug target: Structural characterization of 3, 4-dihydroxy-2-butanone-4-phosphate synthase from Salmonella typhimurium LT2. Pankaj Kumar, Mirage Singh, Ruchi Gautam, and Subramanian Karthikeyan*. Proteins. (2010), 78, 3292-303.


* A Single-Amino-Acid Substitution in the C Terminus of PhoP Determines DNA-Binding Specificity of the Virulence-Associated Response Regulator from Mycobacterium tuberculosis. Arijit Kumar Das, Anuj Pathak, Akesh Sinha, Manish Datt, Balvinder Singh, Subramanian Karthikeyan and Dibyendu Sarkar*. J. Mol. Biol. (2010), 398, 647–656.


* A functional comparison of the TET aminopeptidases of P. furiosus and B. subtilis with a protein-engineered variant recombining the former’s structure with the latter’s active site. Divya Kapoor, Balvinder Singh, Subramanian Karthikeyan, Purnananda Guptasarma?, Enzyme and Microbial Technology. (2010), 46, 1–8.


* Expression, purification, crystallization and preliminary X-ray analysis of maleylacetate reductase from Burkholderia sp. strain SJ98. Archana Chauhan, Zeyaul Islam, Rakesh Kumar Jain* and Subramanian Karthikeyan* Acta Cryst. (2009), F65, 1313–1316.


* Creation of a new eye lens crystallin (Gambeta) through structure-guided mutagenic grafting of the surface of b2 crystallin onto the hydrophobic core of gB crystalline. Divya Kapoor, Balvinder Singh, Karthikeyan Subramanian and Purnananda Guptasarma*. FEBS Journal. (2009), 276, 3341–3353.


* Three Consecutive Arginines Are Important for the Mycobacterial Peptide Deformylase Enzyme Activity*. Rahul Saxena, Pavitra Kanudia, Manish Datt, Haider Hussain Dar, Subramanian Karthikeyan, Balvinder Singh, and Pradip K. Chakraborti*. Journal of Biological Chemistry. (2008), 283, 23754–23764.


* Replacement of the active surface of a thermophile protein by that of a homologous mesophile protein through structure-guided ‘protein surface grafting’. Divya Kapoor, Vijay Kumar, Sanjeev K. Chandrayan, Shubbir Ahmed, Swati Sharma, Manish Datt, Balvinder Singh, Subramanian Karthikeyan*, Purnananda Guptasarma*. Biochimica Biophysica Acta. (2008), 1784, 1771-1776.

* Purification, crystallization and preliminary X-ray diffraction analysis of aspartate semialdehyde dehydrogenase (Rv3708c) from Mycobacterium tuberculosis. Rajan Vyas, Vijay Kumar, Santosh Panjikar, Subramanian Karthikeyan, K. V.Radha Kishan, Rupinder Tewari and Manfred S. Weiss*. Acta Cryst. (2008), F64, 167–170.



* Creation of an active, stable chimeric protein through transplantation of the entire active surface of a protein onto its structural homolog. Divya Kapoor, Vijay Kumar, Sanjeev K. Chandrayan, Shubbir Ahmed, Swati Sharma, Manish Datt, Balvinder Singh, Subramanian Karthikeyan, Purnananda Guptasarma. (2008)

Present group members:


  • Ms. Ruchi Gautam, Research Scholar
  • Ms. Ritika Srivastava, Research Scholar
  • Ms. Suruchi Singh, Research Scholar
  • Ms. Adarsh Kumar, Research Scholar
  • Dr. Ranajit Singh, Postdoctoral Fellow
  • Mr. Surinder Singh, Senior Technician
  • Ms. Sharanjit Kaur, Senior Technician
  • Mr. Senthil Kumar, Technical Assistant

Past group members:

  • Dr. Vijay Kumar
  • Ms. Raj Rani
  • Ms. Anuradha Upadhyay
  • Ms. Shikha Bisht
  • Ms. Sheena
  • Dr. Pankaj Kumar
  • Dr. Mirage Singh
  • Dr. Zeyaul Islam
  • Mr. Prince Tiwari
  • Dr. Prerna Sharma
  • Dr. Savita Yadav
This site is best viewed in Mozilla Firefox, Internet Explorer 8 and above at screen resolution of 1024 x 768 and above.