Banca de QUALIFICAÇÃO: CASSIO SIQUEIRA SOUZA CASSIANO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : CASSIO SIQUEIRA SOUZA CASSIANO
DATE: 22/02/2021
TIME: 14:00
LOCAL: Videoconferência
TITLE:

Identification and functional characterization of the DNA repair enzyme Uracil DNA Glycosylase (Ung) from Corynebacterium pseudotuberculosis

KEY WORDS:

DNA repair, BER, ung, Corynebacterium pseudotuberculosis.

PAGES: 95
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

Corynebacterim pseudotuberculosis is the etiological agent of Lymphadenitis Caseosa (LCA), an infectious disease that is involved with significant losses in the economy in sheep and goat farming in Brazil. The sequencing of the C. pseudotuberculosis genome, carried out by the genome network of Minas Gerais, encouraged genetic studies of this microorganism aiming at the search for therapeutic targets against LCA. In this context, DNA Repair appears as an important study target, since it is a process that aims to maintain genomic integrity, ensuring the survival of any organism. The inefficiency of the DNA repair system can lead the organism to death and the characterization of the genes involved in this system can provide important molecular targets for ACL therapy. Among the repair pathways, BER (Base Excision Repair) is a DNA repair pathway that recognizes and removes damaged or incorrect nitrogenous bases from DNA, such as uracil, resulting from deamination of the cytosine base or by incorrect incorporation base during replication. The enzyme Uracil DNA Glycosylase (Ung) participates in the recognition and repair, avoiding the mutagenic effects caused by the presence of uracil in DNA. Thus, the objective of this work was to characterize the C. pseudotuberculosis Ung protein (CpUng) through in silico and in vitro analyzes. The sequence of the ung gene and the Ung protein were obtained from the Coryneregnet and NCBI databases. The in silico analyzes were performed using tools available on the ExPASy Tools platform and revealed that the CpUng protein belongs to the family of UDG proteins, presenting conserved domains typical of DNA glycosylases. The Cpung gene was cloned into the vector pGEM®-T Easy, subcloned into a bacterial expression vector pET21a and sequenced. The CpUng protein product of the Cpung gene was expressed heterologously in bacterial E. coli Rosetta cells (DE3) and purified using an affinity column to perform the in vitro assays. The in vitro test to assess glycosylase activity using the purified CpUng protein revealed its ability to recognize and excise the uracil base paired with a guanine present in double-stranded DNA. Together, the results found in this work suggest the involvement of the CpUng protein in the repair of the uracil base present in the DNA molecule in C. pseudotuberculosis, being, therefore, an important enzyme for maintaining the genomic stability of this organism.

BANKING MEMBERS:
Presidente - 1682014 - DEBORA DE OLIVEIRA LOPES
Externo ao Programa - 1779894 - HELDER MAGNO SILVA VALADARES
Interna - 1457505 - LUCIANA LARA DOS SANTOS