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عنوان فارسی مقاله:
نوکلئوتید-تبدیل برگشتی دامنه موتور کینسین رایگان به سازش غیر فعال با ویژگی های گلبول مذاب
عنوان انگلیسی مقاله:
Nucleotide-free kinesin motor domains reversibly convert to an inactive conformation with characteristics of a molten globule
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Kinesins are a large superfamily of proteins that share a common motor domain that catalyzes microtubule-activated ATP hydrolysis [1,2]. Most kinesins use the energy of ATP hydrolysis to produce movement along microtubules (MTs), although some also function to depolymerize MTs. The kinesin-1 family was the first to be discovered and is the most extensively studied. In the absence of MTs, kinesin-1 (hereafter just called kinesin) hydrolyzes ATP and releases Pi rapidly, but can only slowly release ADP. Interaction with MTs induces a conformational change that accelerates ADP release [3,4]. Fast binding of ATP or ADP coupled with slow release as ADP results in very tight net binding of ADP. In fact when native heterotetrameric kinesin was isolated from bovine brain, it was found to have retained an ADP at its active site in spite of ATP not having been included in the solutions used in purification [3]. ADP itself, in the absence of Mg2þ, binds only weakly to kinesin and has a fast dissociation rate of ~18 s1 compared to ~0.03 s1 for release of Mg2þ from the Mg2þ complex of E$MgADP and ~0.005 s1 for concerted release of MgADP [5,6]. In the presence of millimolar Mg2þ concentrations, the initial release of Mg2þ at 0.03 s1 is usually followed by rapid Mg2þ rebinding to E$ADP before release of Mg2þ-free ADP can occur. In the presence of excess EDTA, the released Mg2þ is trapped by binding to EDTA and cannot rebind to E$ADP to suppress ADP release. Consequently the net binding of ADP is weak in the presence of excess EDTA. Gel filtration or other methods are now sufficient in the presence of excess EDTA to strip kinesin of its bound ADP. With full length bovine kinesin, this nucleotide-free form was able to rapidly rebind ATP with burst kinetics [4]. A striking early observation was that isolated nucleotide-free motor domains of Drosophila kinesin prepared in this way were, however, unable to rapidly rebind ADP, although they did slowly regain ADP binding during prolonged incubation with ATP [7]. This result is in contrast to the relatively stable apo-form of full length bovine kinesin discussed above. Ma and Taylor were able to stabilize isolated human motor domains in an active nucleotide-free conformation by use of 20% glycerol and high salt or by rapid removal of released ADP by apyrase [8,9]. Although human nucleotide-free motor domains also undergo reversible conversion to a refractory form, the rate of inactivation with human motor domains is slower than for Drosophila motor domains, which allowed for the study of the kinetics of nucleotide binding to active apo-motor domains. Members of the kinesin-5 and kinesin-14families have also been shown to produce an inactive apo-form that can slowly reactivate [10e13]. This report demonstrates that even the more labile Drosophila kinesin motor domains can be stabilized by high concentrations of glycerol and further presents a detailed characterization of the reversible transition between active and refractory conformations of nucleotide-free motor domains. The refractory conformation has properties consistent with that of a molten globule and this is also true of the refractory conformation of Eg5 and Ncd as examples of kinesin-5 and kinesin-14 families. These properties help to explain why crystallization of nucleotide-free kinesin motor domains has been difficult.
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کلمات کلیدی:
Introduction to Genomics - Page 397 - Google Books Result https://books.google.com/books?isbn=0198754833 Arthur Lesk - 2017 Conformational changes arising from interactions with one or more other proteins, ... Some proteins are microscopic motors, interconverting chemical and ... in a metastable active state and convert spontaneously to an inactive native state. ... An enzyme (E) reversibly binds a substrate (S) to form a Michaelis complex (ES). 2. Single-molecule observations of neck linker conformational changes ... www.nature.com › Journal home › Archive › Table of Contents › Article by M Tomishige - 2006 - Cited by 101 - Related articles Oct 1, 2006 - 12-residue peptide) in one motor domain and the rearward positioning of ... To determine the neck linker conformation, FRET efficiencies .... motors that are singly labeled, unbound to microtubules or inactive can ..... Vale, R.D. Conversion of Unc104/KIF1A kinesin into a processive motor after dimerization. The functional domains of bacteriophage T4 terminase Shuji ... www.jbc.org/content/early/2004/07/19/jbc.M403647200.full.pdf by S Kanamaru - 2004 - Cited by 69 - Related articles Jul 19, 2004 - Running title: ATPase and nuclease domains in phage T4 gp17 ... packaging motor drives the 171 kb T4 DNA into the capsid utilizing the free energy ... and that their functions are regulated through conformational ..... characteristic cleaved DNA smear with active terminase constructs, whereas the inactive. [PDF]Structural basis for myosin V discrimination ... - The EMBO Journal embojnl.embopress.org/content/embojnl/25/4/693.full.pdf by N Pashkova - 2006 - Cited by 116 - Related articles Jan 26, 2006 - domain II (Catlett and Weisman, 1998; Schott et al, 1999;. Catlett et al, 2000; Pashkova ... reversible dissociation of the subdomains predict that the dissociation ..... (inactive) conformation where the motor and the cargo- binding domain ... myosin II and involves the interaction of the converter domain of one ... Most recent papers with the keyword Eg5 | Read by QxMD https://www.readbyqxmd.com/keyword/129330 13045 Background: Inhibitors of the Eg5 motor kinesin selectively disrupt mitotic .... kinesin motor domains reversibly convert to an inactive conformation with ...
