Education

PHD, 1969, University of Bombay Haffkine Institute
MSC, 1965, University of Bombay, Haffkine Institute, India
BSC, 1963, University of Poona, C.S. College, Maharashtra

Relevant Publications

K. Singh , and M. J. Modak (1998). A unified DNA- and dNTP-binding mode for DNA polymerases. Trends Biochem. Sci 23 , 277-281.

N. Kaushik, K. Singh, I. Alluru and M. J. Modak (1999). Tyrosine 222, a member of YXDD motif of MuLV RT, is catalytically essential and is a major component of fidelity center. Biochemistry 38 , 2617-2627.

J. Jin, N. Kaushik, K. Singh and M. J. Modak (1999). Analysis of the role of glutamine 190 in the catalytic mechanism of murine leukemia virus reverse transcriptase. J. Biol. Chem . 274 , 20861-2086.

R. Gangurde, N. Kaushik, K. Singh and M. J. Modak, (2000). A carboxylate triad is essential for polymerase activity of Escherichia coli DNA polymerase I (Klenow Fragment): Presence of two functional triads at the catalytic center. J. Biol. Chem . 275: 19685-19692.

S. Tuske*, K. Singh*, N. Kaushik and M. J. Modak (2000). The J-Helix of E. coli DNA Polymerase I (Klenow fragment) Regulates Polymerase and 3'- 5' Exonuclease Functions. J. Biol. Chem. 275 , 23759-23768. (*equal contribution).

K. Singh , N. Kaushik, J. Jin, M. Madhusudanan, and M. J. Modak, (2000). Role of Q190 of MuLV RT in ddNTP resistance and fidelity of DNA synthesis: A molecular model of interactions with substrates. Prot. Eng. 13 , 635-643.

Cindy, J. Arrigo, K. Singh and M. J. Modak (2002). DNA polymerase I from Mycobacterium tuberculosis : Functional role of a conserved aspartate in the hinge joining M and N helices. J. Biol. Chem. 277 :1653-1661.

Gangurde, R.; Modak, M. J (2002). Participation of Active-Site Carboxylates of Escherichia coli DNA Polymerase I (Klenow Fragment) in the Formation of a Prepolymerase Ternary Complex . Biochemistry 41 ; 14552-14559.

Q. Shi*, K. Singh*, A. Srivastava, N. Kaushik and M. J. Modak (2002). Lys152 of MuLV reverse transcriptase is required for the integrity of the active site. Biochemistry 41 : 14831-14842 (*equal contribution).

Srivastava, K. Singh and M. J. Modak (2003) Phe 771 of E.coli DNA polymerase I (Klenow Fragment) is the Major Site for the Interaction with Template Overhang and the Stabilization of Pre-polymerase Ternary Complex. Biochemistry 42 : 3645 ? 3654. K. Singh and M. J. Modak (2003) Presence Of 18 ? Long Hydrogen Bond Track in the Active Site of E.coli DNA Polymerase I (Klenow Fragment): Its Requirement in the Stabilization Of Enzyme -Template - Primer Complex. J. Biol. Chem . 278 : 11289 - 11302.

Areas Of Interest

expression and purification of proteins

3D structures and structural models

DNA polymerase

HIV

M.tb. E.coli

Recombinant enzymes

Reverse tyranscriptase

enzymatic properties

gene cloning

mutagenesis

Course List

MBGC5071Q

Adv. Nucleic Acids: DNA

Strand Displacement synthesis of DNA,involved domains and mechanisms.

The overall objective of this laboratory is to investigate the mechanisms involved in the enzymatic synthesis of DNA. DNA polymerases from E coli, M. tuberculosis, HIV and MuLV sources are included in these studies. Each enzyme study also offers an opportunity to probe in vivo implication of its unique properties, which in turn has importance in drug-design.