共查询到20条相似文献,搜索用时 15 毫秒
1.
Obeid S Schnur A Gloeckner C Blatter N Welte W Diederichs K Marx A 《Chembiochem : a European journal of chemical biology》2011,12(10):1574-1580
DNA is being constantly damaged by endo- and exogenous agents such as reactive oxygen species, chemicals, radioactivity, and ultraviolet radiation. Additionally, DNA is inherently labile, and this can result in, for example, the spontaneous hydrolysis of the glycosidic bond that connects the sugar and the nucleobase moieties in DNA; this results in abasic sites. It has long been obscure how cells achieve DNA synthesis past these lesions, and only recently has it been discovered that several specialized DNA polymerases are involved in translesion synthesis. The underlying mechanisms that render one DNA polymerase competent in translesion synthesis while another DNA polymerase fails are still indistinct. Recently two variants of Taq DNA polymerase that exhibited higher lesion bypass ability than the wild-type enzyme were identified by directed-evolution approaches. Strikingly, in both approaches it was independently found that substitution of a single nonpolar amino acid side chain by a cationic side chain increases the capability of translesion synthesis. Here, we combined both mutations in a single enzyme. We found that the KlenTaq DNA polymerase that bore both mutations superseded the wild-type as well as the respective single mutants in translesion-bypass proficiency. Further insights in the molecular basis of the detected gain of translesion-synthesis function were obtained by structural studies of DNA polymerase variants caught in processing canonical and damaged substrates. We found that increased positive charge of the surface potential in the area proximal to the negatively charged substrates promotes translesion synthesis by KlenTaq DNA polymerase, an enzyme that has very limited naturally evolved capability to perform translesion synthesis. Since expanded positively charged surface potential areas are also found in naturally evolved translesion DNA polymerases, our results underscore the impact of charge on the proficiency of naturally evolved translesion DNA polymerases. 相似文献
2.
3.
4.
5.
6.
Alessia Stornetta Dr. Todor Angelov Prof. Dr. F. Peter Guengerich Prof. Dr. Shana J. Sturla 《Chembiochem : a European journal of chemical biology》2013,14(13):1634-1639
O6‐Methylguanine (O6‐MeG) is a mutagenic DNA lesion, arising from the action of methylating agents on guanine (G) in DNA. Dpo4, an archaeal low‐fidelity Y‐family DNA polymerase involved in translesion DNA synthesis (TLS), is a model for studying how human Y‐family polymerases bypass DNA adducts. Previous work showed that Dpo4‐mediated dTTP incorporation is favored opposite O6‐MeG rather than opposite G. However, factors influencing the preference of Dpo4 to incorporate dTTP opposite O6‐MeG are not fully defined. In this study, we investigated the influence of structural features of incoming dNTPs on their enzymatic incorporation opposite O6‐MeG in a DNA template. To this end, we utilized a new fluorescence‐based primer extension assay to evaluate the incorporation efficiency of a panel of synthetic dNTPs opposite G or O6‐MeG by Dpo4. In single‐dNTP primer extension studies, the synthetic dNTPs were preferentially incorporated opposite G, relative to O6‐MeG. Moreover, pyrimidine‐based dNTPs were generally better incorporated than purine‐based syn‐conformation dNTPs. The results suggest that hydrophobicity of the incoming dNTP appears to have little influence on the process of nucleotide selection by Dpo4, with hydrogen bonding capacity being a major influence. Additionally, modifications at the C2‐position of dCTP increase the selectivity for incorporation opposite O6‐MeG without a significant loss of efficiency. 相似文献
7.
8.
9.
Cover Picture: A Recombinant Collagen–mRNA Platform for Controllable Protein Synthesis (ChemBioChem 10/2015) 下载免费PDF全文
Dr. Liping Sun Yunjing Xiong Dr. Anat Bashan Dr. Ella Zimmerman Dr. Shirley Shulman Daube Dr. Yoav Peleg Dr. Shira Albeck Dr. Tamar Unger Hagith Yonath Miri Krupkin Donna Matzov Prof. Ada Yonath 《Chembiochem : a European journal of chemical biology》2015,16(10):1381-1381
10.
11.
12.
13.
14.
Cover Picture: Fluorogenic Sequencing Using Halogen‐Fluorescein‐Labeled Nucleotides (ChemBioChem 8/2015) 下载免费PDF全文
Zitian Chen Prof. Haifeng Duan Shuo Qiao Wenxiong Zhou Haiwei Qiu Li Kang Prof. X. Sunney Xie Prof. Yanyi Huang 《Chembiochem : a European journal of chemical biology》2015,16(8):1125-1125
15.
16.
17.
Cover Picture: DNA Antenna Tile‐Associated Deoxyribozyme Sensor with Improved Sensitivity (ChemBioChem 21/2016) 下载免费PDF全文
Amanda J. Cox Hillary N. Bengtson Dr. Yulia V. Gerasimova Dr. Kyle H. Rohde Dr. Dmitry M. Kolpashchikov 《Chembiochem : a European journal of chemical biology》2016,17(21):1995-1995
18.
19.