Dissection of Connective Beta -Strand Linkers and Their Role in Enzymatic Activities of Escherichia Coli Leucyl -Trna Synthetase

Individual glycine residues, when mutated to proline, misaminoacylate tRNALeu in spite of retaining efficient amino acid editing activities. It is possible that these mutant LeuRSs may have impaired the translocation of editing substrates between the aminoacylation and editing active sites. An additional T252A mutation within the editing active site in the CP1 was combined with the translocation mutants and these double mutant LeuRSs were characterized in vitro and in vivo. The T252A mutant hydrolyzes both cognate and noncognate amino acids charged to tRNALeu, thereby significantly reducing the yield of charged tRNA. However, beta-strand-based mutants rescue leucylation activity of the T252A mutant LeuRS, suggesting an important role in the translocation pathway. Taken together, this investigation implies a more extensive role for the dynamic beta-strands at different steps of E. coli LeuRS enzyme activity.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Mascarenhas, Anjali Paulette

Contributors dc:contributor

• Martinis, Susan A.

• Chemistry, Biochemistry

Language dc:language

eng

Identifier

(MiAaPQ)AAI3314848

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84851