Inhibitor binding yeast

Additional information <1, 7-9, 12-17, 21> (<7> inhibitory effect of phosphonate analogues of 1,3-diphosphoglycerate, overview [49] <21> no effect by glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-phosphate, pyruvate, phosphoenolpyruvate and lactate [70] <13> double-inhibition studies, kinetics, modeling of inhibitor binding, e.g. phosphate [55] <13> enzyme is regulated by multivalent anions, overview [55] <8> no inhibition by Hg [25] <1,7,9,12-17> yeast enzyme is insensitive to thiol reagents [17]) [17, 25, 49, 55, 70]... 

The mechanism by which MTF-1 facilitates zinc-induction of metallothionein promoter through the MREs is not known, but several models have been proposed. First, zinc may act as a coinducer by binding to MTF-1 and creating an allosteric change, allowing MTF-1 to bind to the MREs. The model proposed for mammalian MTF-l/MRE interaction has already been proven for yeast copper metallothionein systems (Furst et al., 1988). Another possibility may be that, under normal conditions, an inhibitor binds MTF-1. When an influx of zinc occurs, MTF-1 binds the zinc, undergoes a conformational change and is released from the inhibitor. The protein would then have the ability to bind to the MREs. Finally, upon an increase in intracellular zinc concentration, a specific coactivator may bind zinc and interact with MTF-1 to maximally induce transcription. 

Fig. 2 The structures and binding affinities of eight competitive inhibitors of yeast ODCase. R-5 -P represents a 5 -phosphoribosyl group...

FIGURE 16.8 (a) Phosphoglycolohydroxamate is an analog of the enediolate transition state of the yeast aldolase reaction, (b) Purine riboside, a potent inhibitor of the calf intestinal adenosine deaminase reaction, binds to adenosine deaminase as the 1,6-hydrate. The hydrated form of purine riboside is an analog of the proposed transition state for the reaction. 

Fig. 10.7. Inh ibitor binding to individual active sites of the yeast 20S proteasome. The inhibitors lactacystin (A), epoxomicin (B) and TMC95A (C) are colored green and are shown in stereo mode together with their unbiased electron densities. The active-site Thrl is highlighted in black. (A) Covalent binding of the Streptomyces metabolite lactacystin to the active site of 5. The SI pockets of the active subunits and differ from that of 5 and are not suitably constructed to bind the inhibitor. As discussed in the text, Met45 (black), which is located at the bottom of the 5-Sl pocket, makes the difference for inhibitor...

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