Cloning and heterologous expression of ectoine biosynthesis genes from bacillus halodurans in escherichia coli
Cloning and heterologous expression of ectoine biosynthesis genes from bacillus halodurans in escherichia coli
Date
2008
Authors
Rajan, L.A.
Joseph, T.C.
Thampuran, N.
James, R.
Kumar, K.A.
Viswanathan, C.
Bansal, K.C.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Science+Business Media
Abstract
The genes involved in the biosynthetic pathway of ectoine (2-methyl-1,4,5,6-tetrahydropyrimidine-4-carboxylic acid) from Bacillus halodurans were cloned as an operon and expressed in E. coli. Analysis of the deduced ectoine biosynthesis cluster amino acid sequence revealed that the ectoine operon contain 2,389bp, encoded by three genes; ectA, ectB and ectC that encode proteins of 189, 427 and 129 amino acids with deduced molecular masses of 21,048, 47,120 and 14,797Da respectively. Extracts of induced cells showed two bands at 41kDa and 17kDa, possibly corresponding to the products of the later two genes. However the expression of ectA gene could not be ascertained by SDS-PAGE. The activity of the ectA protein was confirmed by an acylation assay. The transgenic E. coli accumulated upto 4.6mg ectoine/l culture. This is the first report of an engineered E. coli strain carrying the ectoine genes of the alkaliphilic bacterium, B. halodurans.
Description
Keywords
Bacillus halodurans, compatible solutes, ectoine genes, osmoregulation
Citation
Biotechnology Letters 2008: 30(8) 1403-1407