Project Details
Projekt
Mechanism of UGA decoding as selenocystein in Gram-positive anaerobic bacteria
Applicant
Professor Dr. Jan Remmer Andreesen, since 6/2002
Subject Area
Biochemistry
Term
from 2000 to 2005
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 5241154
During the process of cotranslational incorporation of selenocysteine into bacterial proteins a special mRNA secondary structure (SECIS, selenocysteine-insertion sequence) is recognized by a the selenocysteine-specific elongation factor SelB to direct insertion of selenocysteine at UGA, a codon which is normally read as a stop signal. The conserved SECIS structure is located directly adjacent to the UGA codon in E. coli and represents part of the coding region. The Gram positive anaerobe Eubacterium acidaminophilum contains the sel genes and has at least 6 selenoproteins of different functions. The inclusion of a conserved SECIS element at a special position within the coding region of these genes to direct selenocysteine incorporation via SelB is therefore more difficult. Analysis of the corresponding genes does not reveal the presence of a common motif such as in E. coli, although some loop structures can be formulated. We therefore want to analyze and characterize the nature of the SECIS elements which might direct selenocysteine incorporation in E. acidaminophilum. These SECIS motifs and their interaction with SelB from E. acidaminophilum will be studied in vitro. Their decoding function will be analyzed in vivo by studies of a heterologous expression of SECIS-lacZ fusions in E. coli in the presence of E. acidaminophilum SelB.
DFG Programme
Priority Programmes
Ehemalige Antragstellerin
Dr. Brigitte Söhling, until 6/2002
