Expression of Wild-Type rcsB Gene Under the pBAD Promoter Restores Capsule Production in Escherichia coli rcsB Mutant and Permits Normal Cell Morphology
Year: 2026
Type: article
Abstract: Previous studies have been inconclusive whether increased capsule size directly confers antibiotic resistance in Escherichia coli. In this study, rcs B gene expression was upregulated using the vector araBAD promoter and induction with varying concentrations of L-arabinose to determine the degree of rcs B involvement in determining capsule size. The rcs B gene was amplified by PCR and cloned into the pBAD-TOPO construct. Restriction digest analysis confirmed that rcs B was present in the correct orientation. Capsule visualization which followed subcloning of the constructs into an rcs B deficient E. coli strain showed restoration of a capsule, but showed little increase in size over wild-type at 2% L-arabinose induction. When the empty pBAD-TOPO vector was transformed into the same rcs B deficient E. coli strain, the L-arabinose induction yielded elongated tubular poles and additional changes in cell morphology. Normal cell morphology was observed for cells containing the pBADrcs B construct. Our results indicate that overexpression of rcs B gene does not greatly enhance capsule formation in the absence of a stimulant and overexpression of empty vectors would not be a suitable control for assessing the role of a cloned gene.
Source: Open Collections
Institution: University of British Columbia
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7222798719
FWCI:
Cites:
Cited by:
Related to: