Applied and Environmental Microbiology (2003) 69, 1023-1029

J. Eleazar Barboza-Corona, Elizabeth Nieto-Mazzocco, Rocio Velázquez-Robledo, Rubén Salcedo-Hernandez, Mayela Bautista, Beatriz Jiménez and Jorge E. Ibarra (2003)
Cloning, sequencing, and expression of the chitinase gene chiA74 from Bacillus thuringiensis
Applied and Environmental Microbiology 69 (2), 1023-1029
Abstract: The endochitinase gene chiA74 from Bacillus thuringiensis serovar kenyae strain LBIT-82 was cloned in Escherichia coli DH5alphaF'. A sequence of 676 amino acids was deduced when the gene was completely sequenced. A molecular mass of 74 kDa was estimated for the preprotein, which includes a putative 4-kDa signal sequence located at the N terminus. The deduced amino acid sequence showed high degree of identity with other chitinases such as ChiB from Bacillus cereus (98%) and ChiA71 from Bacillus thuringiensis serovar pakistani (70%). Additionally, ChiA74 showed a modular structure comprised of three domains: a catalytic domain, a fibronectin-like domain, and a chitin-binding domain. All three domains showed conserved sequences when compared to other bacterial chitinase sequences. A ca. 70-kDa mature protein expressed by the cloned gene was detected in zymograms, comigrating with a chitinase produced by the LBIT-82 wild-type strain. ChiA74 is active within a wide pH range (4 to 9), although a bimodal activity was shown at pH 4.79 and 6.34. The optimal temperature was estimated at 57.2°C when tested at pH 6. The potential use of ChiA74 as a synergistic agent, along with the B. thuringiensis insecticidal Cry proteins, is discussed.
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Database assignments for author(s): J. Eleazar Barboza-Corona, Jorge E. Ibarra

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Bacillus thuringiensis var. kenyae (entomopathogen)
Bacillus thuringiensis var. pakistani (entomopathogen)