Multiple copies of genes coding for electron transport proteins in the bacterium Nitrosomonas europaea.

The genome of Nitrosomonas europaea contains at least three copies each of the genes coding for hydroxylamine oxidoreductase (HAO) and cytochrome c554. A copy of an HAO gene is always located within 2.7 kb of a copy of a cytochrome c554 gene. Cytochrome P-460, a protein that shares very unusual spectral features with HAO, was found to be encoded by a gene separate from the HAO genes.     

Evidence for the Existence of Differential O-Glycosylated α5-Subunits of the γ-Aminobutyric AcidA Receptor in the Rat Brain

Abstract: Polyclonal antibodies were raised to synthetic peptides having amino acid sequences corresponding with the N- or C-terminal part of the γ-aminobutyric acid_A (GABA_A) receptor α₅-subunit. These anti-peptide α₅(2–10) or anti-peptide α₅(427–433) antibodies reacted specifically with GABA_A receptors purified from the brains of 5–10-day-old rats in an enzyme-linked immunosorbent assay and were able to dose-dependently immunoprecipitate up to 6.3 or 13.1% of the GABA_A receptors present in the incubation, respectively. In immunoblots, each of these antibodies reacted with the same two protein bands with apparent molecular mass of 53 or 57 kDa. After exhaustive treatment of purified GABA_A receptors with N -Glycanase, each of these antibodies identified two proteins with apparent molecular masses of 46 and 48 kDa. Additional treatment of GABA_A receptors with neuraminidase and O -Glycanase resulted in an apparently single protein with molecular mass of 47 kDa, which again was identified by both the anti-peptide α₅(2–10) and the anti-peptide α₅(427–433) antibody. These results indicate the existence of at least two different α₅-sub-units of the GABA_A receptor that differ in their carbohydrate content. In contrast to other α- or β-subunits of GABA_A receptors so far investigated, at least one of these two α₅-subunits contains O-linked carbohydrates.     

EMBL-Search: a CD-ROM based database query system

This paper describes a system of generally applicable indexfiles provided on the EMBL sequence databases CD–ROM tofacilitate the development offronz–end software to thesequence databases available on this CD–ROM. The indexfiles are used by a new versatile and user–friendly databaseretrieval program for the Apple Macintosh, EMBL–Search,which allows the easy construction of complex database queries.EMBL–Search utilizes cross–reference informationcontained in the databases to support navigation between differentinformation resources. The ability to run EMBL–Searchon a local computer network accessing a shared database CD–ROMmakes its use particularly cost effective.     

Crevice-forming mutants in the rigid core of bovine pancreatic trypsin inhibitor: crystal structures of F22A, Y23A, N43G, and F45A.

Crystal structures of four mutants of bovine pancreatic trypsin inhibitor (F22A, Y23A, N43G, and F45A), engineered to alter their stability properties, have been determined. The mutated residues, which are highly conserved among Kunitz-type inhibitors, are located in the rigid core of the molecule. Replacement of the partially buried bulky residues of the wild-type protein with smaller residues resulted in crevices open to the exterior of the molecule. The overall three-dimensional structure of these mutants is very similar to that of the wild-type protein and only small rearrangements are observed among the atoms lining the crevices.     

Oxide-Based Solid-State Batteries: A Perspective on Composite Cathode Architecture

The garnet-type phase Li₇La₃Zr₂O₁₂ (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs.     

An Ustilago maydis Mutant Partially Blocked in P45014DM Activity Is Hypersensitive to Azole Fungicides

An Ustilago maydis ergosterol biosynthesis mutant (A14) which is partially blocked in sterol 14alpha-demethylase (P45014DM) activity is described. This mutant accumulated the abnormal 14alpha-methyl sterols, eburicol, 14alpha-methylfecosterol, and obtusifoliol, along with significant amounts of ergosterol. Although the A14 mutant grew nearly as well as the wild type, it was impaired in cell extension growth, which indicated a dysfunction in apical cell wall synthesis. The mutant was also found to be hypersensitive to the azole fungicides penconazole and tebuconazole.     

Methodology in the study of seabass (Lates calcarifer Bloch): nutritional requirements in Singapore

This paper describes the effort of the Marine Aquaculture Section of the Primary Production Department in Singapore and the Institut Francais de Recherche pour l'Exploitation de la Mer in developing adequate facilities for fish nutritional requirement studies in Singapore, and in introducing appropriate nutritional methodology so that results are reliable and accurate. One of the first achievements was the demonstration of homogeneous fish (tropical seabass, Lates calcarifer Bloch) growth response in a newly established tank system before any nutritional experiments were initiated. The application of statistical procedures that take into consideration the power of a test and number of replications required has allowed for more accurate interpretation of results. This can be seen in the results of the first nutritional requirement experiment on the optimal dietary protein level of the seabass at constant energy.     

Two distinct models account for short and long deletions within sequence repeats in Escherichia coli.

In Escherichia coli, (GpC)n sequences cloned into plasmid DNA molecules are deletion-prone with the occurrence of both short (<2 bp) and long (>2 bp) deletion events. These repetitive tracts can be stabilized by interrupting the strict monotony of the repetition with a variant dinucleotide sequence. The stabilization of short deletion events that is mediated by the variant sequence is completely lost in E. coli mismatch repair-deficient strains. In contrast, this repair pathway has no influence on the frequency of occurrence of long deletion events, even in sequences containing the variant repeat. These results lead us to propose two distinct models to account for short and long deletions within repetitive sequences in E. coli. Furthermore, this study reveals that the deletions occur preferentially at the end of the repeat sequence that is distal with respect to the origin of replication.     

The UL20 gene product of pseudorabies virus functions in virus egress.

The UL20 open reading frame is positionally conserved in different alphaherpesvirus genomes and is predicted to encode an integral membrane protein. A previously described UL20- mutant of herpes simplex virus type 1 (HSV-1) exhibited a defect in egress correlating with retention of virions in the perinuclear space (J. D. Baines, P. L. Ward, G. Campadelli-Fiume, and B. Roizman, J. Virol. 65:6414-6424, 1991). To analyze UL20 function in a related but different herpesvirus, we constructed a UL20- pseudorabies virus (PrV) mutant by insertional mutagenesis. Similar to HSV-1, UL20- PrV was found to be severely impaired in both cell-to-cell spread and release from cultured cells. The severity of this defect appeared to be cell type dependent, being more prominent in Vero than in human 143TK- cells. Surprisingly, electron microscopy revealed the retention of enveloped virus particles in cytoplasmic vesicles of Vero cells infected with UL20- PrV. This contrasts with the situation in the UL20- HSV-1 mutant, which accumulated virions in the perinuclear cisterna of Vero cells. Therefore, the UL20 gene products of PrV and HSV-1 appear to be involved in distinct steps of viral egress, acting in different intracellular compartments. This might be caused either by different functions of the UL20 proteins themselves or by generally different egress pathways of PrV and HSV-1 mediated by other viral gene products.