Protein SRP54 iz morske spužve Geodia cydonium

In the systematic search for phylogenetically conserved proteins in the simplest and most ancient extant metazoan phylum – Porifera, we have identified and analyzed a cDNA encoding the signal recognition particle 54 kD protein (SRP54) from the marine sponge Geodia cydonium (Demospongiae). The signal recognition particle (SRP) is a universally conserved ribonucleoprotein complex of a very ancient origin, comprising SRP RNA and several proteins (six in mammals). The nucleotide sequence of the sponge cDNA predicts a protein of 499 amino acid residues with a calculated Mr of 55175. G. cydonium SRP54 displays unusually high overall similarity (90 %) with human/mammalian SRP54 proteins, higher than with Drosophila melanogaster (88 %), or Caenorhabditis elegans (82 %). The same was found for the majority of known and phylogenetically conserved proteins from sponges, indicating that the molecular evolutionary rates in protein coding genes in Porifera as well as in highly developed mammals (vertebrates) are slower, when compared with the rates in homologous genes from invertebrates (insects, nematodes). Therefore, genes/proteins from sponges might be the best candidates for the reconstruction of ancient structures of proteins and genome/proteome complexity in the ancestral organism, common to all multicellular animals.U sistematskoj potrazi za filogenetski sačuvanim proteinima u spužava, najjednostavnijih i najstarijih živućih Metazoa, autori su identificirali i analizirali cDNA koja kodira protein SRP54 u morske spužve Geodia cydonium. SRP54 je evolucijski najsačuvaniji protein ribonukleoproteinskoga kompleksa SRP (signal recognition particle), odgovornog za translokaciju sekretornih i transmembranskih proteina. SRP je nastao vrlo rano u evoluciji i svugdje je prisutan u živom svijetu, od bakterija do čovjeka. cDNA spužve G. cydonium kodira protein SRP54 dug 499 aminokiselina, izračunate molekularne mase 55175, koji pokazuje najviši stupanj sličnosti (90 %) s ljudskim proteinom SRP54, više nego sa SRP54 iz kukca Drosophila melanogaster (88 %) ili oblića Caenorhabditis elegans (82 %). Velika sličnost proteina spužava s homolozima u sisavaca uočena u ovom radu, kao i u našim prijašnjim istraživanjima, upućuje na sporije evolucijske promjene u genima spužava i sisavaca (kralježnjaka) u usporedbi s ubrzanijim promjenama u genima kukaca i oblića (beskralježnjaka). Geni/proteini spužava su stoga posebno korisni za rekonstrukciju strukture proteina i kompleksnosti genoma/proteoma u ancestralnom organizmu koji je bio zajednički predak svih višestaničnih životinja

Nationwide Survey of Klebsiella Pneumoniae Strains Producing CTX-M Extended-spectrum b-lactamases in Croatia

Extended-spectrum β-lactamases (ESBL) producing bacteria have been increasingly reported in both hospital and community patients. Production of ESBLs is the major mechanism of resistance to oxymino-cephalosporins and aztreonam in Gram-negative bacteria 1,2. Recently a new family of ESBLs with predominant activity against cefotaxime (CTX-M β-lactamases) has been reported. Over 80 CTX-M enzymes have been described so far, which can be grouped into five main subgroups according to amino acid sequence identity (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25) 3 . In some countries, CTX-M β-lactamases are the most prevalent types of ESBLs, for instance in Russia 4, Greece 5 , Spain 6 , Switzerland 7, Japan 8, Taiwan 9, China 10 and Argentina 11 . These enzymes have been identified in countries near Croatia such is Italy 12, Hungary13 and Austria14 The aim of this study was to determine the prevalence and the types of CTX-M β lactamases produced by Klebsiella pneumoniae clinical isolates collected from October 2006 to January 2007 from both community- and hospital –based isolates were included (Figure 1.). 128 ESBL isolates were subjected to further analysis: screening with double disc diffusion test and confirmed by ESBL E test 15

Signal Recognition Particle 54 kD Protein (SRP54) from the Marine Sponge Geodia cydonium

In the systematic search for phylogenetically conserved proteins in the simplest and most ancient extant metazoan phylum – Porifera, we have identified and analyzed a cDNA encoding the signal recognition particle 54 kD protein (SRP54) from the marine sponge Geodia cydonium (Demospongiae). The signal recognition particle (SRP) is a universally conserved ribonucleoprotein complex of a very ancient origin, comprising SRP RNA and several proteins (six in mammals). The nucleotide sequence of the sponge cDNA predicts a protein of 499 amino acid residues with a calculated Mr of 55175. G. cydonium SRP54 displays unusually high overall similarity (90 %) with human/mammalian SRP54 proteins, higher than with Drosophila melanogaster (88 %), or Caenorhabditis elegans (82 %). The same was found for the majority of known and phylogenetically conserved proteins from sponges, indicating that the molecular evolutionary rates in protein coding genes in Porifera as well as in highly developed mammals (vertebrates) are slower, when compared with the rates in homologous genes from invertebrates (insects, nematodes). Therefore, genes/proteins from sponges might be the best candidates for the reconstruction of ancient structures of proteins and genome/proteome complexity in the ancestral organism, common to all multicellular animals