Functional and structural characterization of the RNase II-family of enzymes

Dissertation presented to obtain a Doctoral Degree in Biology by Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa

Ribonucleases (RNases) are ubiquitous and have a central role in the control of gene expression. They are involved in the maturation of functional RNAs as well as their degradation. RNases are also involved in quality control mechanisms and are crucial to the recycling of ribonucleotides, key cellular metabolites. Ribonucleases can be broadly classified as endoribonucleases, which cleave at sites internal to the RNA, or exoribonucleases, which remove nucleotides from either the 5' end or 3' end of the RNA molecule. Enzymes from the RNase II-family of exoribonucleases are present in all domains of life, and processively degrade RNA in the 3’ to 5’ direction with a hydrolytic activity that releases 5’-nucleotide monophosphates. They play a crucial role in RNA metabolism and have been shown to be required for normal growth and viability, virulence, mitotic control and chloroplast biogenesis.(...)

Financial Support from Fundação para a Ciência e Tecnologia (FCT). Doctoral Grant - SFRH/BD/36024/2007