Selective cloning of genes encoding RNase H from Salmonella typhimurium, Saccharomyces cerevisiae and Escherichia coli rnh mutant

1991 ◽  
Vol 227 (3) ◽  
pp. 438-445 ◽  
Author(s):  
Mitsuhiro Itaya ◽  
Dorothy McKelvin ◽  
Sunil K. Chatterjie ◽  
Robert J. Crouch
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Salmonella Typhimurium ◽  
Rnase H ◽  
Genes Encoding

How Optimized Is the Translational Machinery in Escherichia coli, Salmonella typhimurium and Saccharomyces cerevisiae?

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Xuhua Xia
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Salmonella Typhimurium ◽  
Codon Usage ◽  
Translational Efficiency ◽  
Square Root ◽  
Translational Machinery ◽  
Mutual Adaptation ◽  
Trna Species

Abstract The optimization of the translational machinery in cells requires the mutual adaptation of codon usage and tRNA concentration, and the adaptation of tRNA concentration to amino acid usage. Two predictions were derived based on a simple deterministic model of translation which assumes that elongation of the peptide chain is rate-limiting. The highest translational efficiency is achieved when the codon recognized by the most abundant tRNA reaches the maximum frequency. For each codon family, the tRNA concentration is optimally adapted to codon usage when the concentration of different tRNA species matches the square-root of the frequency of their corresponding synonymous codons. When tRNA concentration and codon usage are well adapted to each other, the optimal content of all tRNA species carrying the same amino acid should match the square-root of the frequency of the amino acid. These predictions are examined against empirical data from Escherichia coli, Salmonella typhimurium, and Saccharomyces cerevisiae.

Expression of genes encoding two major Theileria annulata merozoite surface antigens in Escherichia coli and a Salmonella typhimurium aroA vaccine strain

Gene ◽  
1996 ◽  
Vol 172 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Christine d'Oliveira ◽  
Edwin J. Tijhaar ◽  
Brian R. Shiels ◽  
Marjo van der Weide ◽  
Frans Jongejan
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Vaccine Strain ◽  
Surface Antigens ◽  
Theileria Annulata ◽  
Expression Of Genes ◽  
Genes Encoding

Cefotaximases (CTX-M-ases), an expanding family of extended-spectrum β-lactamases

2004 ◽  
Vol 50 (3) ◽  
pp. 137-165 ◽  
Author(s):  
Jan Walther-Rasmussen ◽  
Niels Høiby
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Salmonella Typhimurium ◽  
Vibrio Cholerae ◽  
Proteus Mirabilis ◽  
Aeromonas Hydrophila ◽  
Insertion Sequences ◽  
Class A ◽  
Extended Spectrum ◽  
Genes Encoding

Among the extended-spectrum β-lactamases, the cefotaximases (CTX-M-ases) constitute a rapidly growing cluster of enzymes that have disseminated geographically. The CTX-M-ases, which hydrolyze cefotaxime efficiently, are mostly encoded by transferable plasmids, and the enzymes have been found predominantly in Enterobacteriaceae, most prevalently in Escherichia coli, Salmonella typhimurium, Klebsiella pneumoniae, and Proteus mirabilis. Isolates of Vibrio cholerae, Acinetobacter baumannii, and Aeromonas hydrophila encoding CTX-M-ases have also been reported. The CTX-M-ases belong to the molecular class A β-lactamases, and the enzymes are functionally characterized as extended-spectrum β-lactamases. This group of β-lactamases confers resistance to penicillins, extended-spectrum cephalosporins, and monobactams, and the enzymes are inhibited by clavulanate, sulbactam, and tazobactam. Typically, the CTX-M-ases hydrolyze cefotaxime more efficiently than ceftazidime, which is reflected in substantially higher MICs to cefotaxime than to ceftazidime. Phylogenetically, the CTX-M-ases are divided into four subfamilies that seem to have descended from chromosomal β-lactamases of Kluyvera spp. Insertion sequences, especially ISEcp1, have been found adjacent to genes encoding enzymes of all four subfamilies. The class I integron-associated orf513 also seems to be involved in the mobilization of blaCTX-M genes. This review discusses the phylogeny and the hydrolytic properties of the CTX-M-ases, as well as their geographic occurrence and mode of spread.Key words: extended-spectrum β-lactamases, cefotaximases, phylogeny, dissemination, hydrolytic properties.

Organization of genes encoding the L11, L1, L10, and L12 equivalent ribosomal proteins in eubacteria, archaebacteria, and eucaryotes

1989 ◽  
Vol 35 (1) ◽  
pp. 164-170 ◽  
Author(s):  
Lawrence C. Shimmin ◽  
C. Hunter Newton ◽  
Celia Ramirez ◽  
Janet Yee ◽  
Willa Lee Downing ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Ribosomal Proteins ◽  
Sulfolobus Solfataricus ◽  
Mrna Translation ◽  
Restriction Fragments ◽  
E Coli ◽  
Transcription Pattern ◽  
Genes Encoding ◽  
Cytoplasmic Ribosomes

Archaebacterial and eucaryotic cytoplasmic ribosomes contain proteins equivalent to the L11, L1, L10, and L12 proteins of the eubacterium Escherichia coli. In E. coli the genes encoding these ribosomal proteins are clustered, cotranscribed, and autogenously regulated at the level of mRNA translation. Genomic restriction fragments encoding the L11e, L1e, L10e, and L12e (equivalent) proteins from two divergent archaebacteria, Halobacterium cutirubrum and Sulfolobus solfataricus, and the L10e and L12e proteins from the eucaryote Saccharomyces cerevisiae have been cloned, sequenced, and analyzed. In the archaebacteria, as in eubacteria, the four genes are clustered and the L11e, L1e, L 10e, and L12e order is maintained. The transcription pattern of the H. cutirubrum cluster is different from the E. coli pattern and the flanking genes on either side of the tetragenic clusters in E. coli, H. cutirubrum, and Sulfolobus solfataricus are all unrelated to each other. In the eucaryote Saccharomyces cerevisiae there is a single L10e gene and four separate L12e genes that are designated L12eIA, L12eIB, L12eIIA, and L12eIIB. These five genes are not closely linked and each is transcribed as a monocistronic mRNA; the L10e, L12eIA, L12eIB, and the L12eIIA genes are contiguous and uninterrupted, whereas the L12eIIB gene is interrupted by a 301 nucleotide long intron located between codons 38 and 39.Key words: archaebacteria, ribosome, Halobacterium, Sulfolobus.

Enteropathogenic Escherichia coli type III effectors alter cytoskeletal function and signalling in Saccharomyces cerevisiae

Microbiology ◽  
2005 ◽  
Vol 151 (9) ◽  
pp. 2933-2945 ◽  
Author(s):  
Isabel Rodríguez-Escudero ◽  
Philip R. Hardwidge ◽  
César Nombela ◽  
Víctor J. Cid ◽  
B. Brett Finlay ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Effector Proteins ◽  
Type Iii Effectors ◽  
Type Iii ◽  
Genes Encoding ◽  
Cytoskeletal Function ◽  
Enterocyte Effacement ◽  
Functional Analyses ◽  
Map Kinase Pathways

Enteropathogenic Escherichia coli (EPEC) strains cause attaching/effacing lesions in enterocytes through the development of actin-supported pedestals at the site of bacterial adhesion. Pathogenesis requires a type III secretion system (TTSS), which injects into the host cell the intimin receptor, Tir, as well as other effectors called Esps (Escherichia secreted proteins). The genes encoding TTSS structural components and Esps are found within a pathogenicity island called the locus of enterocyte effacement (LEE). This paper describes the application of Saccharomyces cerevisiae as a model to probe the functions of LEE-encoded genes. In a systematic approach, the LEE-encoded translocator and effector proteins were endogenously expressed in yeast and their effects on cell growth, cytoskeletal function and signalling pathways were studied. EspD, EspG and Map inhibited growth by depolarizing the actin cortical cytoskeleton, whereas EspF expression altered the septin cytoskeleton. Specific yeast MAP kinase pathways were activated by EspF, EspG, EspH and Map. The yeast system was used to define functional domains in Map by expressing truncated versions; it was concluded that the C-terminal region of the protein is necessary for actin disruption and toxicity, but not for mitochondrial localization. The utility of the yeast model for functional analyses of EPEC pathogenesis is discussed.

Cloning and constitutive expression of structural genes encoding gonococcal porin protein in Escherichia coli and attenuated Salmonella typhimurium vaccine strains

Gene ◽  
1994 ◽  
Vol 138 (1-2) ◽  
pp. 43-50 ◽  
Author(s):  
Christopher Elkins ◽  
Nicholas H. Carbonetti ◽  
Alex J. Coímbre ◽  
Christopher E. Thomas ◽  
P.Frederick Sparling
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Constitutive Expression ◽  
Structural Genes ◽  
Attenuated Salmonella Typhimurium ◽  
Porin Protein ◽  
Genes Encoding
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