Abstract:
:Site-specific mutagenesis has identified amino acids involved in bR proton transport. Biophysical studies of the mutants have elucidated the roles of two membrane-embedded residues: Asp-85 serves as the acceptor for the proton from the isomerized retinylidene Schiff base, and Asp-96 participates in reprotonation of this group. The functions of Arg-82, Leu-93, Asp-212, Tyr-185, and other residues that affect bR properties when substituted are not as well understood. Structural characterization of the mutant proteins will clarify the effects of substitutions at these positions. Current efforts in the field remain directed at understanding how retinal isomerization is coupled to proton transport. In particular, there has been more emphasis on determining the structures of bR and its photointermediates. Since well-ordered crystals of bR have not been obtained, continued electron diffraction studies of purple membrane offer the best opportunity for structure refinement. Other informative techniques include solid-state nuclear magnetic resonance of isotopically labeled bR (56) and electron paramagnetic resonance of bR tagged with nitroxide spin labels (2, 3, 13, 15). Site-directed mutagenesis will be essential in these studies to introduce specific sites for derivatization with structural probes and to slow the decay of intermediates. Thus, combining molecular biology and biophysics will continue to provide solutions to fundamental problems in bR.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Krebs MP,Khorana HGdoi
10.1128/jb.175.6.1555-1560.1993subject
Has Abstractpub_date
1993-03-01 00:00:00pages
1555-60issue
6eissn
0021-9193issn
1098-5530journal_volume
175pub_type
杂志文章,评审abstract::The Mg-2+-Sarkosyl crystals (M band) procedure was used to study the effect of ribonuclease (RNase) A on the association of Escherichia coli deoxyribonucleic acid (DNA) with membrane. Incubation of gently prepared cell extracts with RNase results in the release of DNA from membrane. This effect appears to result from ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.122.2.592-598.1975
更新日期:1975-05-01 00:00:00
abstract::An abundant 19.3-kDa Helicobacter pylori protein has been cloned, and the sequence is homologous with a ferritin-like protein produced by Escherichia coli K-12. Homologies are also present with a number of eucaryotic ferritins, as well as with the heme group-containing bacterioferritins. All amino acids involved in ch...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.4.966-972.1993
更新日期:1993-02-01 00:00:00
abstract::We report here the identification of a new lipoprotein, NlpI, in Escherichia coli K-12. The NlpI structural gene (nlpI) is located between the genes pnp (polynucleotide phosphorylase) and deaD (RNA helicase) at 71 min on the E. coli chromosome. The nlpI gene encodes a putative polypeptide of approximately 34 kDa, and ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.14.4318-4325.1999
更新日期:1999-07-01 00:00:00
abstract::The genes encoding ammonia monooxygenase (amoCAB), hydroxylamine oxidoreductase (hao), and the c-type cytochrome c-554 (hcy) are present in multiple copies in the genome of Nitrosomonas europaea. The upstream regions of the two copies of amoC, the three copies of hao, and one copy of hcy were cloned and sequenced. Pri...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.3.1096-1100.2001
更新日期:2001-02-01 00:00:00
abstract::Spores of all strains of Dictyostelium discoideum tested in this study germinated after a heat shock of 45 C for 30 min. Whereas the strains differed in their rates of germination, the rate for each strain was constant. A correlation existed between the rate of germination and the rate of vegetative growth when spores...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.5.1690-1695.1968
更新日期:1968-11-01 00:00:00
abstract::The nitrogen assimilation control protein (NAC) binds to a site within the promoter region of the histidine utilization operon (hutUH) of Klebsiella aerogenes, and NAC bound at this site activates transcription of hutUH. This NAC-binding site was characterized by a combination of random and directed DNA mutagenesis. M...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.3.578-585.1998
更新日期:1998-02-01 00:00:00
abstract::A theoretical topology of the Rhodobacter capsulatus membrane protein LhaA was formulated and evaluated by gene fusion experiments. The apparent topological locations of fusion enzymes were compared with the theoretically derived structure, and a model of LhaA is suggested that consists of 12 transmembrane segments, w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.17.4742-4745.1998
更新日期:1998-09-01 00:00:00
abstract::Gill lamellae from the young fruiting bodies of the basidiomycete Coprinus micaceus possess cytoplasmic particles with cytochemically demonstrable acid phosphatase activity; they are presumed to be lysosomes. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.115.1.443-446.1973
更新日期:1973-07-01 00:00:00
abstract::The complete nucleotide sequence of Tn10 has been determined. The dinucleotide signature and percent G+C of the sequence had no discontinuities, indicating that Tn10 constitutes a homogeneous unit. The new sequence contained three new open reading frames corresponding to a glutamate permease, repressors of heavy metal...
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pub_type: 杂志文章
doi:10.1128/jb.182.10.2970-2972.2000
更新日期:2000-05-01 00:00:00
abstract::Proteus swarming is the rapid cyclical population migration across surfaces by elongated cells that hyperexpress flagellar and virulence genes. The mini-Tn5 transposon mutant mns2 was isolated as a tight nonswarming mutant that did not elongate or upregulate flagellar and hemolysin genes. Individual cell motility was ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.15.4741-4746.1997
更新日期:1997-08-01 00:00:00
abstract::No catalase activity was detected in four strains of glucose-grown Mycoplasma pneumoniae at any time during the replication of the organism. Exogenous catalase dramatically increased the O(2) uptake with glycerol, presumably by releasing inhibition caused by hydrogen peroxide. The effect of added catalase on the O(2) ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.4.1425-1430.1968
更新日期:1968-04-01 00:00:00
abstract::Welker, N. E. (Western Reserve University, Cleveland, Ohio and University of Illinois, Urbana), and L. Leon Campbell. De novo synthesis of alpha-amylase by Bacillus stearothermophilus. J. Bacteriol. 86:1202-1210. 1963.-The pH optimum for the synthesis of alpha-amylase by washed-cell suspensions was 6.7. alpha-Amylase ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.86.6.1202-1210.1963
更新日期:1963-12-01 00:00:00
abstract::Chlamydiae are unusual obligately intracellular bacteria that do not synthesize detectable peptidoglycan. However, they possess genes that appear to encode products with peptidoglycan biosynthetic activity. Bioinformatic analysis predicts that chlamydial MurE possesses UDP-MurNAc-L-Ala-D-Glu:meso-diaminopimelic acid (...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01029-09
更新日期:2009-12-01 00:00:00
abstract::In Escherichia coli K-12, two enzymes, encoded by ilvE and tyrB, catalyze the amination of 2-ketoisocaproate (2-KIC) to form leucine. Although leucine-requiring derivatives of an ilvE strain that are unable to grow on 2-KIC were expected to have mutations only in tyrB, mapping studies showed that one such mutation was...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.12.3864-3871.1991
更新日期:1991-06-01 00:00:00
abstract::In the long-chain n-alkane degrader Acinetobacter sp. strain M-1, two alkane hydroxylase complexes are switched by controlling the expression of two n-alkane hydroxylase-encoding genes in response to the chain length of n-alkanes, while rubredoxin and rubredoxin ruductase are encoded by a single gene and expressed con...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.5.1819-1823.2001
更新日期:2001-03-01 00:00:00
abstract::The direct binding of Streptococcus mitis to human platelets is mediated in part by two proteins (PblA and PblB) encoded by a lysogenic bacteriophage (SM1). Since SM1 is the first prophage of S. mitis that has been identified and because of the possible role of these phage-encoded proteins in virulence, we sought to c...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.23.6968-6975.2003
更新日期:2003-12-01 00:00:00
abstract::A new insertion element, IS1549, was identified serendipitously from Mycobacterium smegmatis LR222 during experiments using a vector designed to detect the excision of IS6110 from between the promoter region and open reading frame (ORF) of an aminoglycoside phosphotransferase gene. Six of the kanamycin-resistant isola...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.5.1037-1043.1998
更新日期:1998-03-01 00:00:00
abstract::The antibacterial protein Colicin V (ColV) is secreted from gram-negative bacteria by a signal sequence-independent pathway. The proteins that mediate the export of ColV share sequence similarities with components from other signal sequence-independent export systems such as those for alpha-hemolysin (Hly) and Erwinia...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.23.7549-7556.1991
更新日期:1991-12-01 00:00:00
abstract::Growth and sporulation of a Bacillus subtilis mutant deficient in branched fatty acid synthesis (gene symbol bfmB) were examined. The mutant, which produces an acyl-coenzyme A:acyl carrier protein transacylase with reduced affinity for branched fatty acid primers, could grow in media containing any one of a wide range...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.148.2.480-486.1981
更新日期:1981-11-01 00:00:00
abstract::Bacillus subtilis strains containing deletions in the genes coding for one or two of the major small, acid-soluble spore proteins (SASP; termed SASP-alpha and SASP-beta) were constructed. These mutants sporulated normally, but the spores lacked either SASP-alpha, SASP-beta, or both proteins. The level of minor SASP di...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.167.1.174-178.1986
更新日期:1986-07-01 00:00:00
abstract::Flagellar phase variation of Salmonella is a phenomenon where two flagellin genes, fliC (phase 1) and fljB (phase 2), are expressed alternately. This is controlled by the inversion of a DNA segment containing the promoter for the fljB gene. The fljB gene constitutes an operon with the fljA gene, which encodes a negati...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.3.958-967.2006
更新日期:2006-02-01 00:00:00
abstract::A macrorestriction map representing the complete physical map of the Rhodobacter sphaeroides 2.4.1 chromosomes has been constructed by ordering the chromosomal DNA fragments from total genomic DNA digested with the restriction endonucleases AseI, SpeI, DraI, and SnaBI. Junction fragments and multiple restriction endon...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.11.5850-5859.1989
更新日期:1989-11-01 00:00:00
abstract::Cloning vectors were introduced into Streptococcus faecalis by conjugation. A conjugative plasmid (pVA797) and cloning vector pVA838 recombined in Streptococcus sanguis at homologous sequences, forming a cointegrate. The pVA797::pVA838 cointegrate transferred to S. faecalis by conjugation. Recombination between homolo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.160.3.1109-1114.1984
更新日期:1984-12-01 00:00:00
abstract::Two distinct spore appendage types of Clostridium bifermentans, a pinlike appendage and a tubular appendage, were studied by electron microscopy. The pinlike appendage is characterized by a shaft, about 100 A in diameter, which has a lobed caplike structure. The tubular appendage, 500 to 600 A in diameter, is characte...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.1.231-238.1968
更新日期:1968-01-01 00:00:00
abstract::Virulent bacteria of the genus Yersinia secrete a number of virulence determinants called Yops. These proteins lack typical signal sequences and are not posttranslationally processed. Two gene loci have been identified as being involved in the specific Yop secretion system (G. Cornelis, p. 231-265, In C. E. Hormache, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.9.2619-2626.1994
更新日期:1994-05-01 00:00:00
abstract::The force required to rupture bonds between individual Staphylococcus aureus MSCRAMMs and surfaces coated with extracellular matrix molecules has been quantified by using optical tweezers. The observed binding forces between fibrinogen or fibronectin and S. aureus MSCRAMMs occurred as an approximate integer multiple o...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.6.2031-2035.2003
更新日期:2003-03-01 00:00:00
abstract::Mycoplasma penetrans is a newly identified species of the genus MYCOPLASMA: It was first isolated from a urine sample from a human immunodeficiency virus (HIV)-infected patient. M. penetrans changes its surface antigen profile with high frequency. The changes originate from ON<==>OFF phase variations of the P35 family...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.1.231-242.2003
更新日期:2003-01-01 00:00:00
abstract::Cadmium-resistant Pseudomonas putida GAM-1, which was able to grow in concentrations of CdCl2 as high as 7 mM, was isolated from soil in a rice paddy. This bacterium harbored a DNA plasmid of about 52 kilobases. The plasmid (pGU100) transformed Escherichia coli C600 to cadmium resistance. A cadmium-resistant transform...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.165.1.334-335.1986
更新日期:1986-01-01 00:00:00
abstract::Subgenomic DNA microarrays were employed to evaluate the expression of the accessory gene regulator (agr locus) as well as multiple virulence-associated genes in Staphylococcus aureus. Gene expression was examined during growth of S. aureus in vitro in standard laboratory medium and rabbit serum and in vivo in subcuta...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.4.1095-1101.2002
更新日期:2002-02-01 00:00:00
abstract::It was shown previously that the disruption of the ahrC gene encoding a predicted ArgR family transcription factor results in a severe defect in biofilm formation in vitro, as well as a significant attenuation of virulence of Enterococcus faecalis strain OG1RF in multiple experimental infection models. Using transcrip...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00269-18
更新日期:2018-08-24 00:00:00