Elongation site

Redmond, T., Zigmond, S.H. (1993). Distribution of F-actin elongation sites in lysed polymorphonuclear leukocytes parallels the distribution of endogenous F-actin. Cell Mot. Cytoskel. 26, 7-28. 

Initiation of polymerization. RNA polymerase has two binding sites for NTPs the initiation site for ATP/GTP and the elongation site for substrate NTPs. Most RNA begins with a purine at the 5 -end. The 3 -OH of the first nucleotide at the initiation... 

It had originally been our intention to use -fo UTP as an affinity label for RNA polymerase. However, this triphosphate was a substrate for the enzyme and only produced weak inhibition on reduction of an enzyme-yS-fo UTP mixture. On the other hand, a-fo UTP proved to be a potent inhibitor of the enzyme, and we therefore concentrated our effort on this analog. Although this no longer has the usual p configuration of those triphosphates that are substrates for RNA-polymerase, Rhodes and Chamberlin have shown that the elongation site in the ternary complex has a general affinity for the triphosphate moiety. 

Release from initiation and elongation sites,dinucleotide remains attached to template, enzyme moves, third nucleotide occupies elongation site... 

Typically, ozone cracking initiates at sites of high stress (flaws) on the mbber surface. Thus, in general, mbber articles should be designed to rninirnize potential sites of high elongation such as raised lettering. Similarly, the use of clean molds helps to reduce the incidence of surface flaws. 

Close examination of plate surfaces with a low-power stereomicroscope indicates that the attack sites are cracklike in appearance, but they are actually greatly elongated holes or tunnels that originate at pit sites at the apex of corrugations then propagate down through the plate wall (Fig. 2.26). 

Detailed protein structures have been reported for BPI and CETP. Given the aforementioned similarities within this gene family, these protein structures serve as a likely model for the protein structure of PLTP. CETP and BPI are elongated molecules, shaped like a boomerang. There are two domains with similar folds, and a central beta-sheet domain between these two domains. The molecules contain two lipid-binding sites, one in each domain near the interface of the barrels and the central beta-sheet. 

The microtubule-associated proteins MAP2 and tau both have two separate functional regions (Lewis et al., 1989). One is the microtubule-binding site, which nucleates microtubule assembly and controls the rate of elongation (by slowing the rate of assembly). The second functional domain shared by MAP2 and tau is a short C-terminal a-helical sequence that can cross-link microtubules into bundles by self-interaction. This domain has some of the properties of a leucine zipper. Likely it is responsible for the organization of microtubules into dense stable parallel arrays in axons and dendrites (Lewis et al., 1989). 

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