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dc.contributor.advisorMuniyappa, K
dc.contributor.authorTripathi, Pankaj
dc.date.accessioned2010-09-30T06:16:58Z
dc.date.accessioned2018-07-30T14:14:34Z
dc.date.available2010-09-30T06:16:58Z
dc.date.available2018-07-30T14:14:34Z
dc.date.issued2010-09-30
dc.date.submitted2008
dc.identifier.urihttps://etd.iisc.ac.in/handle/2005/894
dc.description.abstractSaccharomyces cerevisiae HOP1, which encodes a component of the synaptonemal complex, plays an important role in both gene conversion and crossing over between homologs, as well as enforces the meiotic recombination checkpoint control over the progression of recombination intermediates. The zinc-finger motif (Znf) 348CX2CX19CX2C374) of Hop1 is crucial for its function in meiosis, since mutation of conserved Cys371 to Ser in this motif results in a temperature-sensitive phenotype, which is defective in sporulation and meiosis. The direct role for Hop1 or its ZnF in the formation of joint molecules and checkpoint control over the progression of meiotic recombination intermediates is unknown. To understand the underlying biochemical mechanism, we constructed a series of recombination intermediates. Hop1 or its ZnF were able to bind different recombination intermediates. Interestingly, the binding affinity of Hop1 and its ZnF was much higher for the Holliday junction as compared to other recombination intermediates. The complexes of Hop1 or its ZnF with the Holliday junction were stable and specific as shown by NaCl titration and competition experiment. Hop1 and its ZnF blocked BLM helicase-induced unwinding of the Holliday junction, indicating that the interaction between Hop1 and its ZnF with the Holliday junction is specific. DNase I footprinting experiment showed that Hop1 or its ZnF bind to the center of the Holliday junction. 2-aminopurine fluorescence and KMnO4 experiments showed that Hop1 or its ZnF can distort the Holliday junction in a 2-fold symmetrical manner. The molecular modeling study showed that Hop1 ZnF folded into unique helix-loop-helix motif and bound to center of the Holliday junction. In summary, this study shows that Hop1 protein or its ZnF interact specifically with the Holliday junction and distort its structure. Taken together, these results implicate that Hop1 protein might coordinate the physical monitoring of meiotic recombination intermediates during the process of branch migration and that Hop1 ZnF acts as a structural determinant of Hop1 protein functions.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseriesG22423en_US
dc.subjectDNA - Molecular Structureen_US
dc.subjectYeast Hop1 Proteinen_US
dc.subjectHolliday Junctionen_US
dc.subjectHop1 Zinc Fingersen_US
dc.subjectMeiotic Recombinationen_US
dc.subjectMeiosisen_US
dc.subjectSaccharomyces cerevisiaeen_US
dc.subjectHolliday Junction Migrationen_US
dc.subject.classificationBiochemical Geneticsen_US
dc.titleSelective Binding Of Meiosis-Specific Yeast Hop1 Protein, or Its ZnF Motif, To The Holliday Junction Distorts The DNA Structure : Implications For Junction Migration And Resolutionen_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.disciplineFaculty of Scienceen_US


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