Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q17RS7 (Gen)
 130,125 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Arginine and methionine transport by Aspergillus nidulans mycelium was investigated. A single uptake system is responsible for the transport of arginine, lysine and ornithine. Transport is energy-dependent and specific for these basic amino acids. The Km value for arginine is 1 X 10(-5) M, and Vmax is 2-8 nmol/mg dry wt/min; Km for lysine is 8 X 10(-6) M; Kt for lysine as inhibitor of arginine uptake is 12 muM, and Ki for ornithine is mM. On minimal medium, methionine is transported with a Km of 0-I mM and Vmax about I nmol/mg dry wt/min; transport is inhibited by azide. Neutral amnio acids such as serine, phenylalanine and leucine are probably transported by the same system, as indicated by their inhibition of methionine uptake and the existence of a mutant specifically impaired in their transport. The recessive mutant nap3, unable to transport neutral amino acids, was isolated as resistant to selenomethionine and p-fluorophenylanine. This mutant has unchanged transport of methionine by general and specific sulphur-regulated permeases.
J Gen Microbiol 1976 Jan
PMID:Basic and neutral amino acid transport in Aspergillus nidulans. 0 66

Aphids transmitted poly-L-ornithine (PLO)-treated tobacco mosaic virus (TMV) when given acquistion and inoculation access periods as brief as 30 s and 2 min, respectively; the ability to transmit was lost within 90 min. Aphids without claws were able to transmit the virus. Transmission thus seems similar to that of nonpersistent viruses. The ratio of virus to polyamino acid, as well as the KCl concentration, markedly affected transmission. Transmission was best from mixtures which contained 250 mug/ml TMV, 2-5 MUG/ML PLO (mol. wt. 120000) and 0-6 M-KCl. A similar mixture favoured transmission when poly-L-lysine (mol. wt. 85000) was substituted for PLO, but with poly-L-lysine (mol. wt. 30 000) it was necessary to decrease the KCl to 0-3 M to obtain transmission. Less KCl (0-08 to 0-24 M) also favoured aphid transmission of PLO-treated potato virus X and tobacco rattle virus. PLO-treated TMV ultracentrifuged in the presence of, and resuspended in, 0-6 M-KCl remained aphid transmissible while PLO-treated virus in 2 M-DCl, which favours greater dissociation of the virus-PLO complex, was transmissible neither before nor after sedimentation by ultracentrifuging, and resuspension in 0-6 M-KCl. these results show that transmissibility is not due to a permanent alteration of the virus by PLO and indicate that the formation of a TMV-PLO complex is required for transmission. Sequential acquisition experiments suggest that PLO may act by binding TMV to receptor sites in aphids. However, the possibility that PLO affects the infection process was not ruled out.
J Gen Virol 1975 Dec
PMID:Polyamino acid induced aphid transmission of plant viruses. 0 67

Seven strains of viridans streptococci of the species Streptococcus sanguis, S. mutans and S. mitis were investigated for autolysis. The effect of pH, salt concentration and temperature on the autolytic process was studied in Na2HPO4/NaH2PO4 buffer. Whole cells and walls of all strains autolysed most rapidly at pH values above 7. Autolysis of whole cells of S. sanguis and one strain of S. mitis (ATCC15909) was maximal in 0-05 TO 0-2 M buffer, while the two S. mutans strains and S. mitis ATCC15912 showed maximal autolysis in 0-5 and 1-0 M buffers. Cultures harvested in the stationary phase of growth possessed only slightly decreased autolytic activity compared with those from the exponential phase. Whole cells autolysed more rapidly at 37 degrees C Than at 45 degrees C and 10 degrees C. Autolysis of isolated walls of three strains of S. mitis (ATCC903, ATCC15909 and ATCC15912) was maximal at pH 7-0 AND 7-5 and in 1-0 M buffers. Streptococcus mitis ATCC15909 also showed maximal lysis in 0-01 M and 0-5 M buffers. An endopeptidase action of the autolytic system of S. mitis ATCC15912 was indicated by the progressive release of soluble amino groups during autolysis of the walls. No release of reducing groups was observed. Several free amino acids were released during autolysis of these walls, alanine, lysine and glutamic acid being in greatest quanitity.
J Gen Microbiol 1976 Sep
PMID:Autolysis in strains of viridans streptococci. 1 Mar 49

When tris-HCL was used as the buffer for inoculation of tomato protoplasts with tobacco mosaic virus, a greater proportion became infected than when phosphate was used. Using 0-05 M-tris-HCl buffer, pH 8-0, in the presence of poly-L-ornithine or poly-D-lysine, 50 to 80 % infection was obtained.
J Gen Virol 1976 Aug
PMID:The use of tris-HCl buffer for inoculation of tomato protoplasts with tobacco mosaic virus. 1 23

Chemotaxis toward amino acids by Bdellovibrio bacteriovorous strain UKi2 was studied by the capillary technique of Adler (J. Gen. Microbiol. 74:77-91, 1973). Chemotaxis was shown to be optimal when the capillaries were incubated at between 15 and 40 degrees C for 30 min; the optimal pH was between 7.0 and 8.2. The chemotactic response was proportional to the density of the suspension of bdellovibrios up to a density of 10(8) cells/ml. B. bacteriovorus was attracted to L-asparagine, L-cysteine, L-glutamine, glycine, L-histidine, L-lysine, and L-threonine. The possible roles of chemotaxis in the life of B. bacteriovorus are discussed.
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PMID:Chemotaxis toward amino acids by Bdellovibrio bacteriovorus. 1 94

When the pH of growth medium containing a limited amount of inorganic phosphate is kept below 3.0, cells of Saccharomyces cerevisiae produce repressible alkaline phosphatase but no repressible acid phosphatase. The same cells produce acid phosphatase immediately on shifting the medium pH to 4.0 or above. Like intact cells, spheroplasts prepared from cells grown at pH 3.0 or 4.5 in medium with a limited amount of inorganic phosphate in suspension begin production of acid phosphatase immediately after pH shift from below 3.0 to 4.0 whereas sheroplasts from cells grown in inorganic phosphate-rich medium showed a prolonged lag period (3 h). The enzyme formation on the pH shift was sensitive to cycloheximide. No significant differences could be detected in cellular growth or in incorporation of 3H-L-lysine or 14C-adenine between cells cultivated at pH 3.0 and 4.5. These results along with the fact that the expression of structural genes of repressible acid and alkaline phosphatases is controlled by a common genetic regulatory system, at least in part, indicate that the genetic regulatory system operates to express the structural genes even at low pH, though the expression of repressible acid phosphatase is interrupted. Coupled experiments of temperature and pH shifts with the temperature-sensitive mutants of the regulatory genes suggest that the acidic pH affects the function of the cytoplasmic products of those genes in the expression of the structural gene. Based on these observations, a revised model involving the simultaneous functioning of the regulatory factors was suggested for the genetic regulation of repressible acid phosphatase synthesis.
Mol Gen Genet 1978 Jun 14
PMID:Disturbance of the machinery for the gene expression by acidic pH in the repressible acid phosphatase system of Saccharomyces cerevisiae. 2 17

The surface nature of the proteins of a bovine enterovirus have been determined by using 125I and pyridoxal phosphate-sodium borohydride labelling techniques. As found previously, 125I labels only VP1 in intact capsid particles, whereas reaction with pyridoxal phosphate followed by reduction with tritiated sodium borohydride labels VP1, VP2 and VP3. Only VP4 is found to have no surface tyrosine, histidine or lysine available for reaction. After neutralization with homologous antisera, however, VP4 becomes exposed and is then available for labelling with 125I. This must reflect a substantial conformational change in the virus particle after neutralization.
J Gen Virol 1976 Jul
PMID:The surface nature of proteins of a bovine enterovirus, before and after neutralization. 6 Apr 63

The isolation and characterization of 29 new germination (Ger) mutants of Bacillus subtilis 168 is described. These were classified, along with previously described mutants, into seven groups according to map location. The mutations in 26 GerA mutants mapped between cysB and thr; detailed mapping of two of these has located them very close to citG. These mutants were deficient in germination in alanine, but responded to the germinative combination of asparagine, glucose, fructose and KCl. One GerB mutant mapped on the origin-proximal side of hisA; it was normal in germination in alanine, but deficient in termination in a mixture of asparagine, glucose, fructose and KCl. Two GerC mutants were linked to lys, but were separable from a temperature-sensitive growth deficiency mapping between lys and trp. The GerC mutants had a similar germination phenotype to the GerA mutants. Three GerD mutants did not germinate in either of the above germinants or in Penassay Broth. They were located on the side of ery distal to cysA. The GerE mutant, which did not germinate in any of the three germinants, was located very close to citF and possessed an altered spore coat. The two GerF mutants were defective in germination in all three germinants and mapped on the origin proximal-side of hisA, but much closer to his than did the GerB mutant. A phosphoglycerate kinase-negative mutant altered in germination mapped between cysB and hisA (GerG). These mutants have established a minimum of seven locations important to germination, and will be useful in the development and appraisal of theories of spore germination.
J Gen Microbiol 1979 Mar
PMID:Genetics analysis of spore germination mutants of Bacillus subtilis 168: the correlation of phenotype with map location. 11 Sep 6

The inhibitory effect of L-lysine on penicillin biosynthesis by Penicillium chrysogenum has been compared in a low-producing strain (Wis. 54-1255) and a high-producing strain (ASP-78). Lysine inhibited total penicillin synthesis to a similar extent in both strains. However, in the high-producing strain the onset of penicillin synthesis occurred even at a high lysine concentration, whereas in the low-producing strain lysine had to be depleted before penicillin production commenced.
J Gen Microbiol 1979 Nov
PMID:Lysine regulation of penicillin biosynthesis in low-producing and industrial strains of Penicillium chrysogenum. 11 32

The relative genetic position of the following four mutations of ribosomal protein S5 has been determined: spc-13, a mutation to spectinomycin resistance; stri N421 and strid1023, mutations suppressing dependence on streptomycin and sup0-1, a mutation suppressing partially the temperature-sensitive phenotype of an alanyl-tRNA synthetase mutation. The transduction experiments performed indicate that the spc-13 site is located in the S5 cistron proximal to the strA locus, that sup0-1 maps proximal to the aroE gene and that the striN421 and strid1023 loci are located between these two mutational sites. Proteinchemical analysis of the amino acid replacement in protein S5 of strain N421 (carrying the striN421 allele) has shown that an arginine residue is replaced by leucine which results in the appearance of a trypsin intensitive bond between the tryptic peptides T2 and T16. The same alteration has been previously found by Itoh and Wittmann (1973) in the S5 protein of strain d1023. Determination of the alteration of ribosomal protein S5 of strain 0-1 (sup0-1 allele) revealed that the C-terminal tryptic peptide is altered. It differs from that of the wild-type protein by the lack of five amino acids and the appearance of a C-terminal glycine residue instead of a lysine residue. This change can be explained by the deletion of eleven nucleotides in the S5 cistron of strain 0-1. The recent determination of the primary structure of ribosomal protein S5 (Wittmann-Liebold and Greuer, 1975) allows the ordering of the S5 alterations employed: The order is spc-13-strid1023 (striN421)-sup0-1 with the spc-13 amino acid replacement being located at the NH2-terminal portion of the S5 sequence and the alteration of strain 0-1 at the COOH-terminal end. The proteinchemical results are therefore in full agreement with the genetic data and unambiguously allow the conclusion that the S5 cistron is transcribed counterclock-wise on the Escherichia coli chromosome.
Mol Gen Genet 1975 Dec 30
PMID:Genetic position and amino acid replacements of several mutations in ribosomal protein S5 from Escherichia coli. 12 73


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