The Site for Catabolite Deactivation in the L-arabinose BAD Operon in Escherichia Coli B/r
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A series of deletions beginning in the leu operon and continuing into the araC gene and also into the ara controlling site region were analyzed in reciprocal merodiploids, e.g., F' A2Cc67/B24delta719, F' B24delta719/A2Cc67, for their effects on catabolite deactivation (CD). The results of these experiments are consistent with placing the catabolite gene activator-cyclic AMP sensitive site in the controlling site region between araB and araO. With a deletion mutant, delta1109, that places araBAD under leu control when transcription begins at leuP, the araBAD operon is immune to CD even though araCGA, araP and araI are intact and functional. To focus attention on the fine structure and related functions of this region we propose that the three proteins that function therein have separate sites of action: araI (initiator-site for activator), araP (promoter-site for RNA polymerase) and ara(CGA) (catabolite gene activator-site for CGA-cAMP). None of the eighteen initiator constitutive mutants (Ic) tested have any significant effect on catabolite derepression or on the maximal level of expression of the operon supporting the view that the araI site may be distinct from araP and ARA(CGA). A series of constitutive mutants in the araC gene (Cc) also have no pronounced effect on catabolite deactivation.
McMackin E, Corley J, Karash S, Marden J, Wolfgang M, Yahr T J Bacteriol. 2021; 203(16):e0022421.
PMID: 34096777 PMC: 8297530. DOI: 10.1128/JB.00224-21.
Salmonella vaccine vectors displaying delayed antigen synthesis in vivo to enhance immunogenicity.
Wang S, Li Y, Scarpellini G, Kong W, Shi H, Baek C Infect Immun. 2010; 78(9):3969-80.
PMID: 20605977 PMC: 2937466. DOI: 10.1128/IAI.00444-10.
Salmonella enterica serovar typhimurium strains with regulated delayed attenuation in vivo.
Curtiss 3rd R, Wanda S, Gunn B, Zhang X, Tinge S, Ananthnarayan V Infect Immun. 2008; 77(3):1071-82.
PMID: 19103774 PMC: 2643627. DOI: 10.1128/IAI.00693-08.
Functional limits of the araIc promoter suggest an additional regulatory site for araBAD expression.
Horwitz A, Miyada C, Wilcox G J Bacteriol. 1984; 158(1):141-7.
PMID: 6370954 PMC: 215391. DOI: 10.1128/jb.158.1.141-147.1984.
Bankaitis V, Kline E J Bacteriol. 1981; 147(2):500-8.
PMID: 6267010 PMC: 216070. DOI: 10.1128/jb.147.2.500-508.1981.