We investigate the model of "reversible ratchet" with interacting particles, presented by us earlier [F. Slanina, EPL 84, 50009 (2008)]. We further clarify the effect of efficiency enhancement due to interaction and show that it is of energetic origin, rather than a consequence of reduced fluctuations. We also show complicated structures emerging in the interaction and density dependence of the current and response function. The fluctuation properties of the work and input energy indicate in detail the far-from-equilibrium nature of the dynamics.

• MeSH
• chemické modely * MeSH
• molekulární motory chemie   MeSH
• počítačová simulace MeSH
• přenos energie * MeSH
• statistické modely * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• molekulární motory MeSH

The type I restriction-modification enzyme EcoR124I comprises three subunits with the stoichiometry HsdR2/HsdM2/HsdS1. The HsdR subunits are archetypical examples of the fusion between nuclease and helicase domains into a single polypeptide, a linkage that is found in a great many other DNA processing enzymes. To explore the interrelationship between these physically linked domains, we examined the DNA translocation properties of EcoR124I complexes in which the HsdR subunits had been mutated in the RecB-like nuclease motif II or III. We found that nuclease mutations can have multiple effects on DNA translocation despite being distinct from the helicase domain. In addition to reductions in DNA cleavage activity, we also observed decreased translocation and ATPase rates, different enzyme populations with different characteristic translocation rates, a tendency to stall during initiation and altered HsdR turnover dynamics. The significance of these observations to our understanding of domain interactions in molecular machines is discussed.

• MeSH
• adenosintrifosfatasy metabolismus   MeSH
• aminokyselinové motivy MeSH
• biologický transport MeSH
• biotest MeSH
• DNA-helikasy chemie   MeSH
• DNA metabolismus   MeSH
• endonukleasy chemie   MeSH
• Escherichia coli enzymologie   MeSH
• kinetika MeSH
• molekulární motory chemie   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• mutageneze MeSH
• mutantní proteiny chemie   metabolismus   MeSH
• optická pinzeta MeSH
• podjednotky proteinů chemie   metabolismus   MeSH
• restrikční endonukleasy typu I chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• terciární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfatasy MeSH
• DNA-helikasy MeSH
• DNA MeSH
• endodeoxyribonuclease EcoR124I MeSH Prohlížeč
• endonukleasy MeSH
• molekulární motory MeSH
• mutantní proteiny MeSH
• podjednotky proteinů MeSH
• restrikční endonukleasy typu I MeSH

May-Hegglin anomaly (MHA), Sebastian (SBS), Fechtner (FTNS) and Epstein (EPS) syndromes are rare autosomal dominant disorders with giant platelets and thrombocytopenia. Other manifestations of these disorders are combinations of the presence of granulocyte inclusions and deafness, cataracts and renal failure. Currently, MHA, SBS, FTNS and EPS are considered to be distinct clinical manifestation of a single illness caused by mutations of the MYH9 gene encoding the heavy chain of non-muscle myosin IIA (NMMHC-IIA). As the MYH9 gene has a high number of exons, it takes much time and material to use this method for the detection of MYH9 mutations. Recently, a new method has been introduced for scanning DNA mutations without the need for direct sequencing: high-resolution melting analysis (HRMA). Mutation detection with HRMA relies on the intercalation of the specific dye (LC Green plus) in double-strand DNA and fluorescence monitoring of PCR product melting profiles. In our study, we optimized the conditions and used HRMA for rapid screening of mutations in all MYH9 exons in seven affected individuals from four unrelated families with suspected MYH9 disorders. Samples identified by HRMA as positive for the mutation were analysed by direct sequencing. HRMA saved us over 85% of redundant sequencing.

• MeSH
• lidé MeSH
• missense mutace * MeSH
• molekulární motory chemie   genetika   MeSH
• mutační analýza DNA metody   MeSH
• těžké řetězce myosinu chemie   genetika   MeSH
• tranzitní teplota MeSH
• trombocytopenie krev   genetika   MeSH
• trombocyty patologie   MeSH
• velikost buňky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• molekulární motory MeSH
• MYH9 protein, human MeSH Prohlížeč
• těžké řetězce myosinu MeSH