The first described operon was the lactose operon in Escherichia coli, also commonly referred to as the lac operon [3]. How does the lac operon work? The lac operon is required for the transport and metabolism of lactose. The lacI gene is constitutively expressed, meaning that it is ...
λ DE3 = λ sBamHIo ∆EcoRI-B int::(lacI::PlacUV5::T7 gene1) i21 ∆nin5) from New England Biolabs were used for protein expression. Selection vector for DHFR constructs DHFR variants were cloned into a modified version of the pACYC-Duet 1 vector (Novagen), which we refer ...
M15 cells contain the plasmid pREP4, which constitutively expresses the Lac repressor from the lacI gene. S. aureus cells were grown in TSB, and E. coli strains were grown in LB media supplemented with appropriate antibiotics as described below. The low copy number cloning plasmid, pHSG575 (...
H. Catabolite repression of α-amylase gene expression in Bacillus subtilis involves a trans-acting gene product homologous to the Escherichia coli lacI and galR repressors. Mol. Microbiol. 5, 575–584 (1991). The discovery of CcpA in B. subtilis . Used transposon mutagenesis to screen for ...
This vector contains the lacI gene, which encodes the lac repressor. B, overview of the Ub–His10–NextH-Vc7.2 fusion protein. C, nonreducing SDS-polyacrylamide gel of E. coli extracts from untreated cells (lane 1) and cells treated with 1 mm IPTG overnight at 30 °C (lanes 2–4)....
The lac operon contains three genes: lac Z, lac Y, and lac A. The lac Z gene encodes for protein beta-galactosidase, lac Y encodes permease, and lac A encodes transacetylase.Answer and Explanation: The difference between positive and negative regulation...
Lac Operon: The lac operon encodes genes required to break down the sugar lactose in bacteria. It is activated when lactose is present in the environment, and glucose is present in the environment at low levels. Answer and Explanation: ...
The T7 expression system harbors a second lacI gene sequence within its DE3 lysogen, which would, theoretically, double the LacI concentration per cell. The plasmid-based expression systems used in this study were based on the pET plasmid system, which encodes a second lacI gene sequence. In ...
The lac operon provides cells with the ability to switch from glucose to lactose metabolism precisely when necessary. This metabolic switch is mediated by the lac repressor (LacI), which in the absence of lactose binds to the operator DNA sequence to inhibit transcription. Allosteric rearrangements ...
Bbr_0530 (designated here as lntS) encodes a putative solute-binding protein of an ABC transporter system. Located immediately upstream of this cluster, Bbr_0526 (designated lntR) encodes a putative LacI-type transcriptional regulator. We have previously implicated the Bbr_0526-530 gene cluster, ...