Q-Protein

Molecular recognition 113 0 t Q Protein, ssDNA, dsDNA, tRNA, rRNA, mRNA, nRNA, bilayers, ligands, cofactors, metals, autoregulatory... 

Marr, M.T., Datwyler, S.A., Meares, C.F., and Roberts, J.W. (2001) Restructuring of an RNA polymerase holoenzyme elongation complex by lambdoid phage Q proteins. PNAS 98, 8972-8978. 

Answen Q Proteins with SH2 domains might bind to the insulin receptor substrate-1 (IRS-1) to transmit signals from the insulin receptor, a tyrosine kinase type of receptor. PI-3 kinase is an example of an SH2 domain protein. SH2 domains are not involved in DNA binding (choices A and D). Examples of protein domains that bind DNA include zinc fingers (steroid receptors), leudne zippers (CREB protein), and helix-turn-helbc proteins (homeodomain proteins),... 

The Dormant Prophage State of A Is Maintained by a Phage-Encoded Repressor Events That Follow Infection of Escherichia coli by Bacteriophage A Can Lead to Lysis or Lysogeny The N Protein Is an Antiterminator That Results in Extension of Early Transcripts Another Antiterminator, the Q Protein, Is the Key to Late Transcription... 

The phosphoinositide cascade is mediated by 7TM receptors and G q proteins. The receptor-triggered activation of... 

Exion JH. Pfaotphoinosilide phospholipases and Q proteins in hormone action. Anna Rev Physiol 56 349-369,... 

Ray K, KUNSCH C, BCX INER LM, RCAISHAW JD. isolation of cDNA clones encoding eight different human Q protein y subunits, incltiding three novel fonns designated the y4, ylO and yl 1 subunits. JBiol Chem 270 21765-21771,1995. 

Phospholipase C, which inifiafes fhe release of phosphahdylinosifol derivafives, also requires Ca + for achvify. If is difficulf to defermine whether release of Ca + is a primary or secondary response. There are fhree isoenzyme fypes of phospholipase C- 3, y, and 5- and several subforms of each wifh a variety of regulatory mechanisms.For example, the y isoenzymes are activated by binding to the t5a osine kinase domain of receptors such as fhaf for epidermal growfh factor (see Fig. 11-13). In confrasf, fhe (1 forms are offen acfivafed by inhibitory Q proteins and also by Gq, which is specific for inositol phosphate release. 

Genetic map of the regulatory genes of phage k. Genes are listed above the line sites are below the line. The mRNA molecules are heavy lines. The dashed black arrows with thin lines indicate the sites of action of the N, Cro, and Q proteins. 

It should be noted that, apparently, only the complex of coenzyme Q with protein is a really functioning system in native coupling membranes. Although an equilibrium does exist between the free and the bound coenzyme Q, nevertheless the rate of redox transformations of free Q is considerably less than that of other redox systems in the electron transport chain. Possibly, the protein in the Q-protein complex stabilizes the radical Q6H , as a result of which the latter can readily take part in the electron-exchange reaction.31... 

Figure 3. Chemical shlfs (downfleld from TFA) of the trlfluoromethyl-y acetanilide agents in organic solvents vs. their chemical shift in water. The free bromoacetanilides were at 10 mH while labeled proteins were at pH 4.2, " 1 mM. All solutions contained 20% (v/v) 2 corrections were made for bulk susceptibility. Symbols are O, Ethanolt , acetone A, acetonitrile A, dioxeuie , proteins, 6 M urea , proteins, maximum shift at saturating indole Q, proteins alone.

Scheme 1. Schematic drawing of stmcture and function of sMMO. ( Hydroxylase Q Protein B Q Reductase )...

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