Patrícia P. Coltri

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Saccharomyces cerevisiae Nip7p is a nucleolar protein required for accurate processing of the 27S precursor of the 25S and 5.8S ribosomal RNAs. Nip7p homologues are found in eukaryotes and archaea. The Pyrococcus abyssi homologue of Nip7p (PaNip7) was cloned, expressed in Escherichia coli and purified for crystallization. X-ray diffraction data were(More)
NIP7 is one of the many trans-acting factors required for eukaryotic ribosome biogenesis, which interacts with nascent pre-ribosomal particles and dissociates as they complete maturation and are exported to the cytoplasm. By using conditional knockdown, we have shown previously that yeast Nip7p is required primarily for 60S subunit synthesis while human(More)
The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors.(More)
Spliceosome assembly requires several structural rearrangements to position the components of the catalytic core. Many of these rearrangements involve successive strengthening and weakening of different RNA:RNA and RNA:proteins interactions within the complex. To gain insight into the organization of the catalytic core of the spliceosome arrested between(More)
The conserved protein Nip7 is involved in ribosome biogenesis, being required for proper 27S pre-rRNA processing and 60S ribosome subunit assembly in Saccharomyces cerevisiae. Yeast Nip7p interacts with nucleolar proteins and with the exosome subunit Rrp43p, but its molecular function remains to be determined. Solution of the Pyrococcus abyssi Nip7 (PaNip7)(More)
Splicing of primary transcripts is an essential process for the control of gene expression. Specific conserved sequences in premature transcripts are important to recruit the spliceosome machinery. The Saccharomyces cerevisiae catalytic spliceosome is composed of about 60 proteins and 5 snRNAs (U1, U2, U4/U6 and U5). Among these proteins, there are core(More)
Eukaryotic ribosome biogenesis requires the function of a large number of trans-acting factors which interact transiently with the nascent pre-rRNA and dissociate as the ribosomal subunits proceed to maturation and export to the cytoplasm. Loss-of-function mutations in human trans-acting factors or ribosome components may lead to genetic syndromes. In a(More)
Biological networks pervade nature. They describe systems throughout all levels of biological organization, from molecules regulating metabolism to species interactions that shape ecosystem dynamics. The network thinking revealed recurrent organizational patterns in complex biological systems, such as the formation of semi-independent groups of connected(More)
Xylella fastidiosa was the first phytopathogen to be completely sequenced, and its genome revealed several interesting features to be used in functional studies. In the present work, the htpX gene, which encodes a protein involved in the heat shock response in other bacteria, was analyzed by RT-PCR by using cells derived from different cultural conditions.(More)
Xylella fastidiosa is a xylem-limited phytopathogen responsible for diseases in several plants such as citrus and coffee. Analysis of the bacterial genome revealed some putative pathogenicity-related genes that could help to elucidate the molecular mechanisms of plant–pathogen interactions. In the present work, the transcription of three genes of the(More)