Thermodynamic, Spectroscopic, and Equilibrium Binding Studies of DNA Sequence Context Effects in Six 22-Base Pair Deoxyoligonucleotides

Biochemistry ◽  
1999 ◽  
Vol 38 (34) ◽  
pp. 11197-11208 ◽  
Author(s):  
Peter V. Riccelli ◽  
Peter M. Vallone ◽  
Irina Kashin ◽  
Brian D. Faldasz ◽  
Michael J. Lane ◽  
...  
2012 ◽  
Vol 287 (44) ◽  
pp. 36702-36710 ◽  
Author(s):  
Akira Sassa ◽  
William A. Beard ◽  
Rajendra Prasad ◽  
Samuel H. Wilson

1991 ◽  
Vol 11 (1) ◽  
pp. 218-225
Author(s):  
B A Kunz ◽  
X L Kang ◽  
L Kohalmi

Inactivation of the Saccharomyces cerevisiae RAD18 gene confers a mutator phenotype. To determine the specificity of this effect, a collection of 212 spontaneous SUP4-o mutants arising in a rad18 strain was characterized by DNA sequencing. Comparison of the resulting mutational spectrum with that for an isogenic wild-type (RAD18) strain revealed that the rad18 mutator specifically enhanced the frequency of single base pair substitutions. Further analysis indicated that an increase in the frequency of G.C----T.A transversions accounted for the elevated SUP4-o mutation frequency. Thus, rad18 is the first eucaryotic mutator found to generate only a particular base pair substitution. The majority of G.C pairs that were not mutated in the rad18 background were at sites where G.C----T.A events can be detected in SUP4-o, suggesting that DNA sequence context influences the rad18 mutator effect. Transformation of heteroduplex plasmid DNAs into the two strains demonstrated that the rad18 mutator did not reduce the efficiency of correcting G-A or C-T mismatches to G.C pairs or preferentially correct the mismatches to A.T pairs. We propose that the RAD18 gene product might contribute to the fidelity of DNA replication in S. cerevisiae by involvement in a process that serves to limit the formation of G-A and C-T mismatches at template guanine and cytosine sites during DNA synthesis.


1991 ◽  
Vol 11 (1) ◽  
pp. 218-225 ◽  
Author(s):  
B A Kunz ◽  
X L Kang ◽  
L Kohalmi

Inactivation of the Saccharomyces cerevisiae RAD18 gene confers a mutator phenotype. To determine the specificity of this effect, a collection of 212 spontaneous SUP4-o mutants arising in a rad18 strain was characterized by DNA sequencing. Comparison of the resulting mutational spectrum with that for an isogenic wild-type (RAD18) strain revealed that the rad18 mutator specifically enhanced the frequency of single base pair substitutions. Further analysis indicated that an increase in the frequency of G.C----T.A transversions accounted for the elevated SUP4-o mutation frequency. Thus, rad18 is the first eucaryotic mutator found to generate only a particular base pair substitution. The majority of G.C pairs that were not mutated in the rad18 background were at sites where G.C----T.A events can be detected in SUP4-o, suggesting that DNA sequence context influences the rad18 mutator effect. Transformation of heteroduplex plasmid DNAs into the two strains demonstrated that the rad18 mutator did not reduce the efficiency of correcting G-A or C-T mismatches to G.C pairs or preferentially correct the mismatches to A.T pairs. We propose that the RAD18 gene product might contribute to the fidelity of DNA replication in S. cerevisiae by involvement in a process that serves to limit the formation of G-A and C-T mismatches at template guanine and cytosine sites during DNA synthesis.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gianluca Trinco ◽  
Valentina Arkhipova ◽  
Alisa A. Garaeva ◽  
Cedric A. J. Hutter ◽  
Markus A. Seeger ◽  
...  

AbstractIt is well-established that the secondary active transporters GltTk and GltPh catalyze coupled uptake of aspartate and three sodium ions, but insight in the kinetic mechanism of transport is fragmentary. Here, we systematically measured aspartate uptake rates in proteoliposomes containing purified GltTk, and derived the rate equation for a mechanism in which two sodium ions bind before and another after aspartate. Re-analysis of existing data on GltPh using this equation allowed for determination of the turnover number (0.14 s−1), without the need for error-prone protein quantification. To overcome the complication that purified transporters may adopt right-side-out or inside-out membrane orientations upon reconstitution, thereby confounding the kinetic analysis, we employed a rapid method using synthetic nanobodies to inactivate one population. Oppositely oriented GltTk proteins showed the same transport kinetics, consistent with the use of an identical gating element on both sides of the membrane. Our work underlines the value of bona fide transport experiments to reveal mechanistic features of Na+-aspartate symport that cannot be observed in detergent solution. Combined with previous pre-equilibrium binding studies, a full kinetic mechanism of structurally characterized aspartate transporters of the SLC1A family is now emerging.


2008 ◽  
Vol 283 (51) ◽  
pp. 35569-35578 ◽  
Author(s):  
Yelena Margolin ◽  
Vladimir Shafirovich ◽  
Nicholas E. Geacintov ◽  
Michael S. DeMott ◽  
Peter C. Dedon

Biochemistry ◽  
1999 ◽  
Vol 38 (3) ◽  
pp. 1144-1152 ◽  
Author(s):  
Ingrid Pontén ◽  
Jane M. Sayer ◽  
Anthony S. Pilcher ◽  
Haruhiko Yagi ◽  
Subodh Kumar ◽  
...  

1988 ◽  
Vol 8 (2) ◽  
pp. 978-981
Author(s):  
C N Giroux ◽  
J R Mis ◽  
M K Pierce ◽  
S E Kohalmi ◽  
B A Kunz

A collection of 196 spontaneous mutations in the SUP4-o gene of the yeast Saccharomyces cerevisiae was analyzed by DNA sequencing. The classes of mutation identified included all possible types of base-pair substitution, deletions of various lengths, complex alterations involving multiple changes, and insertions of transposable elements. Our findings demonstrate that at least several different mechanisms are responsible for spontaneous mutagenesis in S. cerevisiae.


1984 ◽  
Vol 4 (4) ◽  
pp. 591-598
Author(s):  
J Cappello ◽  
C Zuker ◽  
H F Lodish

The Dictyostelium genome contains 40 copies of a 4.7-kilobase repetitive and apparently transposable DNA sequence (DIRS-1) and about 250 smaller elements that appear to be deletions or rearrangements of DIRS-1. Transcripts of these sequences are induced during differentiation and also by heat shock treatment of growing cells. We showed that one such cloned element, pB41.6 (2.5 kilobases) contains a nucleotide sequence identical to the Drosophila consensus heat shock promotor. To test whether this sequence might indeed control the expression of DIRS-1-related RNAs, we have cloned this genomic segment into yeast cells. In yeast cells, 41.6 directs synthesis of a 1.7-kilobase RNA that is induced at least 10-fold by heat shock. Transcription initiates at about 124 bases 3' of the putative promotor sequence and terminates within the 41.6 insert. A 381-base-pair subclone that contains the putative promotor sequence is sufficient to induce the heat shock response of 41.6 in yeast cells.


1989 ◽  
Vol 9 (3) ◽  
pp. 1351-1356 ◽  
Author(s):  
D L Zhang ◽  
K C Ehrlich ◽  
P C Supakar ◽  
M Ehrlich

A novel, 5-methylcytosine-specific, DNA-binding protein, DBP-m, has been identified in nuclear extracts of peas. DBP-m specifically recognizes 5-methylcytosine residues in DNA without appreciable DNA sequence specificity, unlike a mammalian DNA-binding protein (MDBP), which recognizes 5-methylcytosine residues but only in a related family of 14-base-pair sequences.


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