A New cry2Ab Gene 185 Applied Biochemistry and Biotechnology Vol. 128, 2006 Copyright © 2006 by Humana Press Inc. All rights of any nature whatsoever reserved. 0273-2289/1559-0291 (Online)/06/128/0185/$30.00 185 *Author to whom all correspondence and reprint requests should be addressed. Cloning, Characterization, and Expression of a New cry2Ab Gene From Bacillus thuringiensis Strain 14-1 DEVENDRA JAIN, V. UDAYASURIYAN,* P. INDRA ARULSELVI, SONA S. DEV, AND P. SANGEETHA Department of Plant Molecular Biology and Biotechnology, Centre for Plant Molecular Biology, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu, India, E-mail: udayvar@yahoo.com Received July 9, 2005; Revised August 29, 2005; Accepted September 9, 2005 Abstract Bacillus thuringiensis is the major source for transfer of genes to impart insect resistance in transgenic plants. Cry2A proteins of B. thuringiensis are promising candidates for management of resistance development in insects owing to their difference from the currently used Cry1A proteins, in struc- ture and insecticidal mechanism. The cry2Ab gene was found to lack a func- tional promoter and, hence, is cryptic in nature. The cry2Ab7 gene was cloned from a new indigenous B. thuringiensis strain, 14-1. Nucleotide sequencing of the cry2Ab gene cloned from B. thuringiensis strain 14-1 revealed an open read- ing frame of 1902 bp. The deduced amino acid sequence of Cry2Ab of B. thuringiensis strain 14-1 showed a variation in three amino acid residues in comparison to the holotype sequence, Cry2Ab1. Expression of the newly cloned cry2Ab gene was studied in an acrystalliferous strain of B. thuringiensis (4Q7) by fusing the cry2Ab gene downstream of cry2Aa promoter and orf1 + orf2 sequences. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of a spore–crystal mixture obtained from transformants of B. thuringiensis strain 4Q7 showed production of Cry2Ab protein of about 65 kDa. Alkali solubilized Cry2Ab7 protein showed toxicity against Helicoverpa armigera neonates. Index Entries: Bacillus thuringiensis; δ-endotoxin; Cry2Ab7; cry2Aa pro- moter; cloning; Helicoverpa armigera. Introduction Bacillus thuringiensis is a well-known Gram-positive, spore-forming soil bacterium that forms insecticidal crystal proteins during the sporulation