ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
The Escherichia coli cytotoxic necrotizing factor 1 (CNF1) is organized into three functional domains: the N-terminal part containing the cell-binding domain, a putative central membrane-spanning region, and a C-terminal catalytic region. On the basis of competition assays between CNF1 and GST-recombinant proteins containing different N-terminal fragments, and point mutations, we restricted the binding region to the first 190 amino acids. Hydrophilic amino acids 53–75 are strictly necessary to cell receptor recognition. Using different cnf1–lacZ translational fusions, we demonstrated that the mRNA corresponding to the first 48 codons of cnf1 is involved in the translational regulation of CNF1 synthesis. This regulation consists of both a positive and a negative control. The positive control is exerted by codons 6–20, including a putative downstream box that enhances the translational expression of cnf1. The negative control depends on codons 45–48. In this region, an anti-Shine–Dalgarno sequence, highly homologous to the core of the internal complementary sequence already reported for growth rate-regulated metabolic genes, has been detected. To some extent, the inner structural organization of CNF1 would thus suggest the compiling of several functions in a single mRNA protein system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2958.1999.01453.x
