CHAPTER 18 LECTURE NOTES: CONTROL OF GENE
... 3. The enzyme lactose permease transports lactose into the cell and is encoded by the lacY gene. 4. The genes are transcribed from a polycistronic mRNA along with the lacA gene. 5. There is a promoter region that controls lac expression. 6. There is an operator region to which a repressor binds (see ...
... 3. The enzyme lactose permease transports lactose into the cell and is encoded by the lacY gene. 4. The genes are transcribed from a polycistronic mRNA along with the lacA gene. 5. There is a promoter region that controls lac expression. 6. There is an operator region to which a repressor binds (see ...
Fusion protein
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
Chpt15_PosNegCntrl.doc
... A wild-type cell has only about 10 molecules of the repressor tetramer. Isolation and purification of the protein was greatly aided by use of mutant strain with up-promoter mutations for lacI, so that many more copies of the protein were present in each cell. This general strategy of over-producing ...
... A wild-type cell has only about 10 molecules of the repressor tetramer. Isolation and purification of the protein was greatly aided by use of mutant strain with up-promoter mutations for lacI, so that many more copies of the protein were present in each cell. This general strategy of over-producing ...
Repressor protein - Edwin C. Foreman High School
... if bacterium encounters new sugar (energy source), like lactose, then it needs to start making enzymes used to digest lactose ...
... if bacterium encounters new sugar (energy source), like lactose, then it needs to start making enzymes used to digest lactose ...
chapter13
... Some genes encode for proteins that are always needed. These genes are constantly transcribed. They are called constitutive genes. E.g. enzymes needed for glycolysis. Most regulated genes in bacteria are organized into operons. Operons permit coordinated control of functionally related genes. An ope ...
... Some genes encode for proteins that are always needed. These genes are constantly transcribed. They are called constitutive genes. E.g. enzymes needed for glycolysis. Most regulated genes in bacteria are organized into operons. Operons permit coordinated control of functionally related genes. An ope ...
CHEM523 Final Exam Possible
... You begin your purification by performing an ammonium sulfate (AS) precipitation. You add the appropriate concentration of AS to your CL sample, incubate overnight at 4°C, then centrifuge to generate a supernatant (AS-S) and pellet (AS-P). a) What concentration of AS will you use to precipitate β-ga ...
... You begin your purification by performing an ammonium sulfate (AS) precipitation. You add the appropriate concentration of AS to your CL sample, incubate overnight at 4°C, then centrifuge to generate a supernatant (AS-S) and pellet (AS-P). a) What concentration of AS will you use to precipitate β-ga ...
EMS-treated culture
... Most prokaryotic genes are regulated in units called operons (Jacob and Monod, 1960) Operon: a coordinated unit of gene expression consisting of one or more related genes and the operator and promoter sequences that regulate their transcription. The mRNAs thus produced are “polycistronic’—multiple g ...
... Most prokaryotic genes are regulated in units called operons (Jacob and Monod, 1960) Operon: a coordinated unit of gene expression consisting of one or more related genes and the operator and promoter sequences that regulate their transcription. The mRNAs thus produced are “polycistronic’—multiple g ...
Recombinant DNA Technology Manipulation of Gene Expression in
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
Recombinant DNA Technology Manipulation of Gene Expression in
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
Slides
... But CAP won’t bind if the cell is already using a better fuel (eg, glucose). How does CAP know whether it should be binding or not? ...
... But CAP won’t bind if the cell is already using a better fuel (eg, glucose). How does CAP know whether it should be binding or not? ...
Oc - TUM
... enhanceosome: complexes of regulatory proteins that interact in cooperative and synergistic fashion --> high levels of transcription through recruitment of RNA pol II ...
... enhanceosome: complexes of regulatory proteins that interact in cooperative and synergistic fashion --> high levels of transcription through recruitment of RNA pol II ...
Recombinant DNA Technology Manipulation of Gene Expression in
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
... A simple E. coli expression vector utilizing the lac promoter. In the presence of the lactose analog IPTG, RNA polymerase normally transcribes the lacZ gene, producing lacZ mRNA, which is translated into the encoded protein, G-CSF ...
CHAPTER 13 – PROKARYOTE GENES: E. COLI LAC OPERON
... or (2) produces a polypeptide that cannot bind to the operator sequence. Note that these two alleles would have different genetic sequences, but the phenotype is the same. Theoretically, we should have better locus names to properly identify specific alleles, but for ...
... or (2) produces a polypeptide that cannot bind to the operator sequence. Note that these two alleles would have different genetic sequences, but the phenotype is the same. Theoretically, we should have better locus names to properly identify specific alleles, but for ...
repressor
... • The repressor can be in an active or inactive form, depending on the presence of other molecules • A corepressor is a molecule that cooperates with a repressor protein to switch an operon off • For example, E. coli can synthesize the amino acid tryptophan ...
... • The repressor can be in an active or inactive form, depending on the presence of other molecules • A corepressor is a molecule that cooperates with a repressor protein to switch an operon off • For example, E. coli can synthesize the amino acid tryptophan ...
Ch 15 Clicker Question
... external medium, the E. coli bacterium brings in the tryptophan and does not need to make this amino acid. Which is true when there is no tryptophan in the medium? A. The repressor is active and binds to the operator. B. The repressor is inactive, and RNA polymerase moves through the operator. C. Th ...
... external medium, the E. coli bacterium brings in the tryptophan and does not need to make this amino acid. Which is true when there is no tryptophan in the medium? A. The repressor is active and binds to the operator. B. The repressor is inactive, and RNA polymerase moves through the operator. C. Th ...
lesson x - MisterSyracuse.com
... 2. What tells RNA polymerase to start or stop? 3. What tells DNA polymerase to start or stop? New Learning: (30 minutes) 1. What we need to find out is how genes are controlled. We don’t want them on all the time, but we don’t want them off all the time, either. 2. In prokaryotes, things called oper ...
... 2. What tells RNA polymerase to start or stop? 3. What tells DNA polymerase to start or stop? New Learning: (30 minutes) 1. What we need to find out is how genes are controlled. We don’t want them on all the time, but we don’t want them off all the time, either. 2. In prokaryotes, things called oper ...
Control of Gene Expression Control of Gene Expression Regulatory
... • The trp operon is negatively regulated by the trp repressor protein – trp repressor binds to the operator to block transcription – binding of repressor to the operator requires a corepressor which is tryptophan – low levels of tryptophan prevent the repressor from binding to the operator ...
... • The trp operon is negatively regulated by the trp repressor protein – trp repressor binds to the operator to block transcription – binding of repressor to the operator requires a corepressor which is tryptophan – low levels of tryptophan prevent the repressor from binding to the operator ...
Regulation of Gene Expression
... Regulator gene- this codes for a DNA-binding protein that acts as a repressor Promoter – DNA sequence that binds RNA polymerase Operator- portion of DNA where an active repressor binds Structural Genes- codes for enzymes and proteins needed for the operons metabolic pathway ...
... Regulator gene- this codes for a DNA-binding protein that acts as a repressor Promoter – DNA sequence that binds RNA polymerase Operator- portion of DNA where an active repressor binds Structural Genes- codes for enzymes and proteins needed for the operons metabolic pathway ...
Gene Expression PreTest
... 8. When lactose is absent, ______________________ __________________ can bind to the promoter and transcription can occur in the lac operon. 9. The lac operon is switched off when a protein called a(n) ______________________ is bound to the operator. 10. In eukaryotic gene regulation, proteins calle ...
... 8. When lactose is absent, ______________________ __________________ can bind to the promoter and transcription can occur in the lac operon. 9. The lac operon is switched off when a protein called a(n) ______________________ is bound to the operator. 10. In eukaryotic gene regulation, proteins calle ...
Virus Structure and Method of Invasion
... (b) Lactose present, repressor inactive, operon on. Allolactose, an isomer of lactose, derepresses the operon by inactivating the repressor. In this way, the enzymes for lactose utilization are induced. ...
... (b) Lactose present, repressor inactive, operon on. Allolactose, an isomer of lactose, derepresses the operon by inactivating the repressor. In this way, the enzymes for lactose utilization are induced. ...
Chapter 18 - Operons - Foothill Technology High
... Recall that lactose breaks down into glucose and galactose. Low glucose levels signals the cell for more lactose to be broken down. Both conditions must be met for the lac operon to turn on. ...
... Recall that lactose breaks down into glucose and galactose. Low glucose levels signals the cell for more lactose to be broken down. Both conditions must be met for the lac operon to turn on. ...
regulation-2013
... 8-Regulation by protein stability •Ubiquitin-dependent proteolysis. Cyclins control of cell cycle. • Protein molecule is tagged for degradation by attachment of a 20 kDa protein, ubiquitin ...
... 8-Regulation by protein stability •Ubiquitin-dependent proteolysis. Cyclins control of cell cycle. • Protein molecule is tagged for degradation by attachment of a 20 kDa protein, ubiquitin ...
Nucleic acid recognition from prokaryotes to eukaryotes: Case
... Proteins regulate gene expression at multiple stages ranging from transcription through RNA processing and translation. At each stage, regulatory proteins overcome diverse problems of molecular recognition to associate with the target nucleic acid and respond to cellular signals. This seminar descri ...
... Proteins regulate gene expression at multiple stages ranging from transcription through RNA processing and translation. At each stage, regulatory proteins overcome diverse problems of molecular recognition to associate with the target nucleic acid and respond to cellular signals. This seminar descri ...
Regulation
... lactose, derepresses the operon by inactivating the repressor. In this way, the enzymes for lactose utilization are induced. ...
... lactose, derepresses the operon by inactivating the repressor. In this way, the enzymes for lactose utilization are induced. ...
Lac operon
lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes at universities for this reason.Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA. The gene product of lacZ is β-galactosidase which cleaves lactose, a disaccharide, into glucose and galactose. LacY encodes lactose permease, a protein which becomes embedded in the cytoplasmic membrane to enable transport of lactose into the cell. Finally, lacA encodes galactoside O-acetyltransferase. Layout of the lac operon.It would be wasteful to produce the enzymes when there is no lactose available or if there is a more preferable energy source available, such as glucose. The lac operon uses a two-part control mechanism to ensure that the cell expends energy producing the enzymes encoded by the lac operon only when necessary. In the absence of lactose, the lac repressor halts production of the enzymes encoded by the lac operon. In the presence of glucose, the catabolite activator protein (CAP), required for production of the enzymes, remains inactive, and EIIAGlc shuts down lactose permease to prevent transport of lactose into the cell. This dual control mechanism causes the sequential utilization of glucose and lactose in two distinct growth phases, known as diauxie.