negative regulatory proteins bind to operator sequences in the dna and prevent or weaken rna...

14

Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

Upload: justin-blake

Post on 18-Dec-2015

219 views

Category:

Documents

0 download

Report

Download

Tags:

Embed Size (px):

TRANSCRIPT

Page 1: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

Negative regulatory proteins bind to operator sequencesin the DNA and prevent or weaken RNA polymerase binding

Page 2: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

Most prokaryotic mRNA molecules are polycistronic, theyencode multiple genes. These genes are usually involved in the same biochemical event.

A single promoter controls the expression of these genes.

This functional unit of DNA is called an operon.

Page 3: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

A classical example oftranscriptional regulation

is lactose metabolismin E. coli.

Proteins required for lactose metabolism inE. coli are encoded by

the lac operon.

Page 4: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

The E. coli lac operon

lacI – encodes the Lac repressor proteinlacZ – encodes b-galactosidaselacY – encodes galactose permeaselacA – encodes transacetylaseO2 and O3 are pseudooperators

Page 5: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

The Lac repressor protein is thought to bind to the main operatorand one of the pseudooperators, forming a loop in the DNA.

Page 6: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

When lactose is present in high concentrations, the lactose metabolismgene products are needed in a cell. In the absence of lactose, the Lac repressor protein binds to the operator in the DNA, repressingtranscription. The Lac repressor, however, binds to allolactose, ametabolite of lactose, inducing a conformational change that abolishesbinding to the DNA operator sequence. Transcription is no longer repressed.

- allolactose transparent+ allolactose bold

Page 7: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

DNA binding proteins contain amino acids that hydrogen bond tofunctional groups in the major groove of DNA.

Page 8: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

DNA sequences recognized by regulatory proteins are often inverted repeats of a short DNA sequence. These repeats form a palindrome with two-fold symmetry about a central axis. Regulatory proteins are often dimeric. Each subunit binds to one strand of the DNA.

5’-TACGGTACTGTGCTCGAGCACTGCTGTACT-3’3’-ATGCCATGACACGAGCTCGTGACGACATGA-5’

central axis

Page 9: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

The Lac repressor protein

The Lac repressor is a tetramer of four identicalprotein subunits.

There are DNA-bindingdomains on each subunitshown in blue.

The allolactose binding domain (green) is connectedto the DNA binding domain through linker helices (yellow).

Tetramerization domains (red)form contacts between subunits.

Page 10: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

The Lac repressor protein

The Lac repressor is a tetramer of four identicalprotein subunits.

There are DNA-bindingdomains on each subunitshown in blue.

The allolactose binding domain (green) is connectedto the DNA binding domain through linker helices (yellow).

Tetramerization domains (red)form contacts between subunits.

Page 11: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

The DNA binding domains of the Lac repressor contain a helix-turn-helix motif, a structure critical for the interaction of many

proteins with DNA.

helix

turnhelix

Page 12: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

Lac repressor protein

(lacI)

Page 13: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

Lac repressor bound to DNA

Page 14: Negative regulatory proteins bind to operator sequences in the DNA and prevent or weaken RNA polymerase binding

Lac repressor bound to DNA

Subsidies weaken the sustainability of global fisheries ... · Subsidies weaken the sustainability of global fisheries while increasing inequality among fishers U. Rashid Sumaila

DNA, RNA, and Protein - booksite.elsevier.com · Additionally, a component of RNA polymerase, called a sigma factor, enables the enzyme to bind to different promoters. There are numerous

Microbial Genetics - Duncan Rossduncanross.net/MIC2010/_ch_08_lecture_presentation.pdf · DNA polymerase. DNA polymerase digests RNA primer DNA . polymerase . DNA polymerase Okazaki

Does Global Warming Weaken Tornadoes - Berkeley Earthberkeleyearth.org › static › pdf › berkeley-earth-truth-about-tornadoes.… · Does%Global%Warming%Weaken%Tornadoes?% %

Controls Over Genes. More on Transcription zPromoters are regions on DNA that show where RNA Polymerase must bind to begin the Transcription of RNA zCalled

DNA polymerase fidelity and the polymerase chain reaction. › alan.ward › Molecular... · DNA Polymerase Fidelity and the Polymerase Chain Reaction Kristin A. Eckert and Thomas

BIND 9 Administrator Reference Manual · BIND 9 Administrator Reference Manual ... iii BIND 9.11.4-P1. ... Conﬁguring BIND 9 for Solaris with the SCA 6000 . . . . . . . . . .

Regulation of Gene Expression - BiolympiadsThe trp operon (trp for tryptophan) is one of many operons in the E. coli genome. By itself, an operon is turned on: RNA polymerase can bind

Initiation of rDNA transcription Two transcription factors, UBF and SL1, bind cooperatively to the rDNA promoter and recruit RNA polymerase I to form an

DNA RNA Protein Reverse transcriptase RNA-dependent RNA polymerase DNA polymerase RNA polymerase Ribosome Enzymes in the central dogma Cellular enzymes

Factors that weaken democracies

KM - StrengthenKM - Strengthen and Weaken.pdf and Weaken

Gene Expression Prokaryotesbiotech.gsu.edu/4564/media/lecture17'21.pdfA repressor stops RNA polymerase from initiating Transcription factors enable RNA polymerase to bind to the promoter

DNS and BIND Security - FRUUG• Subscribe to bind-users or bind9-users –bind-users is gatewayed to comp.protocols.dns.bind –Subscribe by sending mail to [email protected]

The Polymerase Chain Reaction (PCR) file/molecular... · What is the Polymerase Chain Reaction? • Chain reaction by DNA polymerase resulting ... Microsoft PowerPoint

a. DNA ligase b. DNA polymerase c. RNA polymerase d. Restriction enzyme

Subsidies weaken the sustainability of global fisheries

How did the Great Depression weaken Germany?

Polymerase Chain Reaction - uvm.edubiology/Classes/296D/4_PCR.pdf · PCR 1. Separate the Double Helix 2. Bind primers (2) to sequence you want to replicate 3. DNA Polymerase copies

DON’T WEAKEN SOUTH CAROLINA’S GUN LAWS: REJECT …

Polymerase Chain Reaction - bmg.fc.ul.ptbmg.fc.ul.pt/Disciplinas/GBM/aulas/5PCR.pdf · Denature DNA sample to separate DNA strands (94ºC, 5 min) Primer bind to DNA strands (30-65ºC,

Red Hat system-config-bind BIND (Berkeley Internet Name …raymond.chan/ops535/1201/... · 2012. 1. 10. · # rpm -q bind bind-9.3.1 The string “9.3.1” is the version of BIND

Polymerase Chain Reaction (PCR) - ITK diagnostics bv Polymerase... · Polymerase Chain Reaction (PCR) ... DNA polymerase, dNTPs, MgCl2 and reaction buffers are provided at optimized

dna replication - sciencetoat.weebly.com · DNA Replication Enzymes topoisomerases RNA primase DNA helicase DNA polymerase I ... • single-stranded binding proteins (SSBs) bind to

· present Rate x) indicate Trade Agreoment 1933 e x) ... by fernentation processes ag ... Orange juice 00 50 Bind 0925 Bind Bind Bind Bind

Grupo BIND - NY SEPT 18 · 2018. 11. 7. · BIND GROUP NET INCOME BIND Inversiones - Valores BIND Inversiones - Asset Management BIND Seguros Credicuotas Tienda Jubilo BIND Banco

Polymerase Chain Reaction

Platinum Taq DNA Polymerase High Fidelity€¦ · Platinum® Taq DNA Polymerase High Fidelity contains recombinant Taq DNA polymerase, Pyrococcus species GB-D polymerase, and Platinum®