Active transport across the vacuolar components of the eukaryotic endomembrane system is energized by a specific vacuolar H+-ATPase. The amino acid sequences of the 70-and 60-kDa subunits of the vacuolar H+-ATPase are -25% identical to the .8 and a subunits, respectively, of the eubacterial-type FOFj-ATPases. We now report that the same vacuolar H+-ATPase subunits are -50% identical to the a and 13 subunits, respectively, of the sulfur-metabolizing Sulfolobus acidocaldarius, an archaebacterium (Archaeobacterium). Moreover, the homologue of an 88-amino acid stretch near the amino-terminal end of the 70-kDa subunit is absent from the FOFj-ATPase P subunit but is present in the a subunit of Sulfolobus. Since the two types of subunits (a and 13 subunits; 60-and 70-kDa subunits) are homologous to each other, they must have arisen by a gene duplication that occurred prior to the last common ancestor of the eubacteria, eukaryotes, and Sulfolobus. Thus, the phylogenetic tree of the subunits can be rooted at the site where the gene duplication occurred. The inferred evolutionary tree contains two main branches: a eubacterial branch and an eocyte branch that gave rise to Sulfolobus and the eukaryotic host cell. The implication is that the vacuolar H+-ATPase of eukaryotes arose by the internalization of the plasma membrane H+-ATPase of an archaebacterial-like ancestral cell.Recently, attention has focused on the evolutionary relationships among the H+-ATPases, particularly the F0F1-ATPases (F-type) and vacuolar (V-type) H+-ATPases. F-and VATPases exhibit a number of structural and functional similarities (1-4). Both are large, multisubunit enzymes (=500 kDa) composed of a water-soluble catalytic sector and an integral membrane proton channel complex. Each hydrophilic sector contains three copies of the catalytic subunit (F-ATPase (3 subunit or V-ATPase 70-kDa subunit), three copies of a regulatory subunit (F-ATPase a subunit or V-ATPase 60-kDa subunit), and one copy each of several minor subunits (4). Sequences obtained for several eukaryotic V-ATPase 70-and 60-kDa subunits confirmed that the Fand V-type H+-ATPases are indeed homologous (5-9). However, the low overall similarity (25%) and the presence of a large stretch of nonhomologous sequence in the 70-kDa subunit (5) suggest that they diverged early in evolution. Consistent with this view, sequences obtained for the two major subunits of the membrane H+-ATPase of Sulfolobus acidocaldarius, an archaebacterium (Archaeobacterium), indicated that the "archaebacterial-type" H+-ATPase is only distantly related to the eubacterial-type F-ATPases (10, 11). In this joint communication from four of the laboratories involved, we show that the H+-ATPase of S. acidocaldarius belongs in the V-ATPase class of proton pumps. The implications for the origin of eukaryotes are discussed. MATERIALS AND METHODSTo determine the evolutionary relationships among the different H+-ATPases, protein or DNA sequences coding for the two major subunits or parts of these subunits were aligned, ...

The present pharmacokinetic study indicates that 8 g of fosfomycin three times per day should provide sufficient antimicrobial concentrations in the CSF for the overall treatment period. Thus, the co-administration of fosfomycin could be useful for the treatment of ventriculitis caused by susceptible pathogens.

Nepenthaceae are an exceptional family with regard to carnivory and the uniformity of characters. This makes it difficult to resolve phylogenetic relationships due to convergent evolution of morphological features. Using comparative sequencing of the chloroplast trnK intron, the monophyly of this complex family and hypotheses of infrageneric relationships were tested. Sequences from 71 Nepenthes taxa, representing all groups and two taxa of the closely related Ancistrocladaceae and Dioncophyllaceae as outgroup, were determined and analysed using maximum parsimony methods. Results of this analysis show that the isolated taxa N. distillatoria (Sri Lanka) and N. pervillei (Seychelles) are the most basal, clearly separated from the Madagascan taxa N. madagascariensis and N. masoalensis which are placed in a distinct subclade. This corresponds with some plesiomorphic characters shared by these taxa. N. khasiana (North India) has an intermediate position between these relic Western species and the remaining taxa. The species of the Malay Archipelago can be referred to three distinct lineages which indicate a correlation to biogeography. Thus the recent disjunct distribution of Nepenthes is interpreted as a result of an incisive extinction of progenitors, a process of migration and a subsequent diversification on the islands of Borneo, Sumatra, Sulawesi and New Guinea. Based on our molecular data, two interpretations concerning the origin of Nepenthes are possible: i) evolution in the Northern Tethys which is supported by fossil pollen records from the European Focene, or, ii) a Gondwanaland origin at a time when the Indian plate was separated from Madagascar. Molecular data indicate that colonization of SE Asia started from an ancient Indian stock. Subsequently, in the Malay Archipelago a new secondary centre of diversity developed. Madagascar, the Seychelles and New Caledonia were probably reached by migration via land bridges, starting from widespead common ancestors with subsequent extinction leaving the current taxa. There is no evidence for long‐distance dispersal. Current infragenic classification of Nepenthes is only partly in accordance with the phylogeny inferred from trnK intron data.

Despite intensive morphological, chemical and cladistic studies on Caryophyllidae, the circumscription of this subclass and the interfamilial relationships are still under discussion. Using comparative sequencing of the chloroplast matK gene, hypotheses of relationships between the carnivorous Droseraceae, Nepenthaceae and Dioncophyllaceae and ten other families of the Caryophyllidae s.l. were tested and compared with previously published cladograms based on rbcL, 18S rDNA and ORF2280 sequences. Parsimony analyses indicate two well‐differentiated clades. One strongly supported clade comprises the carnivorous families Droseraceae and Nepenthaceae, along with its close relatives Dioncophyllaceae and Ancistrocladaceae. The second clade is restricted to the Polygonaceae, Plumbaginaceae, Tamaricaceae and Frankeniaceae. The Simmondsiaceae are more closely related to Caryophyllales and are at the base of the remaining taxa. Results of this analysis suggest that carnivory within Caryophyllidae s.l. has a monophyletic origin and, with the exception of Triphyophyllum, this syndrome was lost in the taxa of Dioncophyllaceae and Ancistrocladaceae. The exclusion of Drosophyllum from Droseraceae suggests no close relationship with this family. Finally, the data support a sister group relationship between the Plumbaginaceae and Polygonaceae and the Frankeniaceae and Tamaricaceae. An extensive survey of the rpl2 intron via PCR amplification indicates that the intron is absent from chloroplast genomes of Droseraceae and all taxa of Caryophyllales, but is present in Drosophyllum. Consequently, there is evidence for a multiple loss of the intron and strong support that Drosophyllum has affinities outside the Droseraceae. Our sequence data corroborate many aspects of recent cladistic analyses based predominantly on rbcL sequences. This study shows that matK sequences are useful for'phylogenetic inference among closely related members of Caryophyllidae.

The phytochrome gene (phyCer) of the moss Ceratodon purpureus was isolated and characterized. phyCer is composed of three coding exons: exon I of 2035 bp, exon II of 300 bp and exon III of 1574 bp. The deduced polypeptide encoded by exon I and II exhibits substantial sequence homology to the conserved NH2-terminal chromophore domain of known phytochromes. In contrast, the COOH-terminal polypeptide encoded by exon III shows no sequence homology to any phytochrome molecule. phyCer most likely represents a single-copy gene and is expressed in a light-independent manner. From the DNA sequence analysis it can be deduced that the PhyCer polypeptide is composed of 1303 amino acids (including the starting Met) which predicts a molecular mass for PhyCer of 145 kDa. The polypeptide encoded in exon III exhibits striking homology within the 300 carboxy-terminal amino acids to the catalytic domain of protein kinases. The carboxy terminus of PhyCer was found to be most homologous to protein-tyrosine kinases of Dictyostelium discoideum and to the products of retroviral oncogenes which belong to the Raf-Mos serine/threonine kinase family. From the hydropathy profile PhyCer appears to be a soluble protein. The predicted structure suggests that PhyCer represents a soluble light-sensor protein kinase which is linked with a cellular phosphorylating cascade.

Fosfomycin is a broad-spectrum antibiotic which is established as therapy for uncomplicated lower urinary tract infections. In addition, preliminary data indicate that fosfomycin has a potential role in the treatment of soft tissue infections. However, the use of fosfomycin has not been established for this condition, and it is unclear whether the level of fosfomycin penetration into human soft tissues is high enough to eradicate relevant pathogens. To better characterize the antibiotic potential of fosfomycin, we applied a combined in vivo pharmacokinetic-in vitro pharmacodynamic model to human volunteers. In corresponding in vitro simulation experiments with selected isolates of Staphylococcus aureus, Enterobacter cloacae, and Serratia marcescens for which MICs were 16 g/ml, organisms were undetectable after a single dosing interval. Fosfomycin exhibits a strong ability to penetrate into the fluid of the interstitial space of soft tissues and reaches levels sufficient to substantially inhibit the growth of relevant bacteria at the target site. We therefore conclude that fosfomycin might qualify as an alternative candidate for the therapy of soft tissue infections.

Phosphoenolpyruvate carboxykinase has been found in significant activities in a number of plants exhibiting Crassulacean

No abstract