Region sequence, operating

Floquet et al. (1985) proposed a tree searching algorithm in order to synthesize chemical processes involving reactor/separator/recycle systems interlinked with recycle streams. The reactor network of this approach is restricted to a single isothermal CSTR or PFR unit, and the separation units are considered to be simple distillation columns. The conversion of reactants into products, the temperature of the reactor, as well as the reflux ratio of the distillation columns were treated as parameters. Once the values of the parameters have been specified, the composition of the outlet stream of the reactor can be estimated and application of the tree searching algorithm on the alternative separation tasks provides the less costly distillation sequence. The problem is solved for several values of the parameters and conclusions are drawn for different regions of operation. 

How do repressor and Cro recognize the specific operator regions and achieve this subtle differential binding to the switch regions The sequences of ORl, 0R2, and OR3 in lambda are similar but not identical (Table 8.1). They are... 

Table 8.1 The nucleotide sequences of the three protein-binding regions ORl, OR2, and OR3 of the operator of bacteriophage lambda...

Approximately 10 base pairs are required to make one turn in B-DNA. The centers of the palindromic sequences in the DNA-binding regions of the operator are also separated by about 10 base pairs (see Table 8.1). Thus if one of the recognition a helices binds to one of the palindromic DNA sequences, the second recognition a helix of the protein dimer is poised to bind to the second palindromic DNA sequence. 

Sequence-specific protein-DNA interactions recognize operator regions... 

Figure 8.15 Sequence-specific protein-DNA interactions provide a general recognition signal for operator regions in 434 bacteriophage, (a) In this complex between 434 repressor fragment and a synthetic DNA there are two glutamine residues (28 and 29) at the beginning of the recognition helix in the helix-turn-helix motif that provide such interactions with the first three base pairs of the operator region.

The proteins impose precise distortions on the B-DNA in the complexes Sequence-specific protein-DNA interactions recognize operator regions... 

The N-terminal A/B region whose structure has not yet been defined contains a transcriptional activation function, referred to as activation function 1 (AF-1), which can operate autonomously. The length and sequence of the A/B region in the different NRs are highly variable, revealing a very weak evolutionary... 

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