Abstract:
UNLABELLED:Bacterial type IV coupling proteins (T4CPs) bind and mediate the delivery of DNA substrates through associated type IV secretion systems (T4SSs). T4CPs consist of a transmembrane domain, a conserved nucleotide-binding domain (NBD), and a sequence-variable helical bundle called the all-alpha domain (AAD). In the T4CP structural prototype, plasmid R388-encoded TrwB, the NBD assembles as a homohexamer resembling RecA and DNA ring helicases, and the AAD, which sits at the channel entrance of the homohexamer, is structurally similar to N-terminal domain 1 of recombinase XerD. Here, we defined the contributions of AADs from the Agrobacterium tumefaciens VirD4 and Enterococcus faecalis PcfC T4CPs to DNA substrate binding. AAD deletions abolished DNA transfer, whereas production of the AAD in otherwise wild-type donor strains diminished the transfer of cognate but not heterologous substrates. Reciprocal swaps of AADs between PcfC and VirD4 abolished the transfer of cognate DNA substrates, although strikingly, the VirD4-AADPcfC chimera (VirD4 with the PcfC AAD) supported the transfer of a mobilizable plasmid. Purified AADs from both T4CPs bound DNA substrates without sequence preference but specifically bound cognate processing proteins required for cleavage at origin-of-transfer sequences. The soluble domains of VirD4 and PcfC lacking their AADs neither exerted negative dominance in vivo nor specifically bound cognate processing proteins in vitro. Our findings support a model in which the T4CP AADs contribute to DNA substrate selection through binding of associated processing proteins. Furthermore, MOBQ plasmids have evolved a docking mechanism that bypasses the AAD substrate discrimination checkpoint, which might account for their capacity to promiscuously transfer through many different T4SSs. IMPORTANCE:For conjugative transfer of mobile DNA elements, members of the VirD4/TraG/TrwB receptor superfamily bind cognate DNA substrates through mechanisms that are largely undefined. Here, we supply genetic and biochemical evidence that a helical bundle, designated the all-alpha domain (AAD), of T4SS receptors functions as a substrate specificity determinant. We show that AADs from two substrate receptors, Agrobacterium tumefaciens VirD4 and Enterococcus faecalis PcfC, bind DNA without sequence or strand preference but specifically bind the cognate relaxases responsible for nicking and piloting the transferred strand through the T4SS. We propose that interactions of receptor AADs with DNA-processing factors constitute a basis for selective coupling of mobile DNA elements with type IV secretion channels.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Whitaker N,Chen Y,Jakubowski SJ,Sarkar MK,Li F,Christie PJdoi
10.1128/JB.00189-15subject
Has Abstractpub_date
2015-07-01 00:00:00pages
2335-49issue
14eissn
0021-9193issn
1098-5530pii
JB.00189-15journal_volume
197pub_type
杂志文章abstract::The gene that encodes the acyl carrier protein (ACP) of the actinorhodin polyketide synthase (PKS) of Streptomyces coelicolor A3(2) was replaced with homologs from the granaticin, oxytetracycline, tetracenomycin, and putative frenolicin polyketide synthase gene clusters. All of the replacements led to expression of fu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.8.2197-2204.1993
更新日期:1993-04-01 00:00:00
abstract::In bacteria, normal mutation frequencies are mostly around 10(-10) per base pair. However, there exists natural isolates, called "mutators," that exhibit permanent mutation occurrences up to 1,000-fold greater than usual. As mutations play essential roles, particularly in the evolution of antibiotic resistance, bacter...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00498-12
更新日期:2012-07-01 00:00:00
abstract::The TspO outer membrane protein of Rhodobacter sphaeroides has been shown to be involved in controlling the transcription of a number of genes which encode enzymes involved in photopigment biosynthesis and the puc operon. The display of regulated genes appears identical to those genes encompassing the PpsR/AppA repres...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.21.6355-6364.2001
更新日期:2001-11-01 00:00:00
abstract::Two mutations in the ninR region of bacteriophage lambda that bypass a requirement for antitermination have been studied. One mutation, byp, has been cloned and mapped by marker rescue to a 417-base-pair segment in the ninR region of the genome. Analysis of the byp mutation by using promoter detection vectors, DNA seq...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.8.4610-4615.1990
更新日期:1990-08-01 00:00:00
abstract::The antiadaptor protein IraD inhibits the proteolysis of the alternative sigma factor, RpoS, which promotes the synthesis of >100 genes during the general stress response and during stationary phase. Our previous results showed that IraD determines RpoS steady-state levels during exponential growth and mediates its st...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00412-09
更新日期:2009-12-01 00:00:00
abstract::Certain group VIIIB transition metal compounds were found to inhibit cell division in Escherichia coli, causing marked filamentous growth. Gram-negative bacilli were the most sensitive to this effect, whereas gram-positive bacilli responded only at near-toxic levels of the metal. None of the cocci tested showed any ap...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.93.2.716-721.1967
更新日期:1967-02-01 00:00:00
abstract::OxyR is a DNA binding protein that differentially regulates a cell's response to hydrogen peroxide-mediated oxidative stress. We previously reported that the reduced form of OxyR is sufficient for repression of transcription of agn43 from unmethylated template DNA, which is essential for deoxyadenosine methylase (Dam)...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.7.2203-2209.2003
更新日期:2003-04-01 00:00:00
abstract::Two lipopolysaccharide O-antigen-specific monoclonal antibodies, MA1-8 (an immunoglobulin G1 [IgG1]) and MF15-4 (an IgM), were used to localize the O antigen of the lipopolysaccharide of Pseudomonas aeruginosa PAO1. A protein A-dextran-gold conjugate with an average particle diameter of 12.5 nm was used to label bacte...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3531-3538.1987
更新日期:1987-08-01 00:00:00
abstract::The tsr gene specifies a methyl-accepting membrane protein involved in chemotaxis to serine and several repellent compounds. We have characterized a special class of tsr mutations designated cheD which alter the signaling properties of the Tsr transducer. Unlike tsr null mutants, cheD strains are generally nonchemotac...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.1.96-104.1985
更新日期:1985-01-01 00:00:00
abstract::Two different 30-nucleotide regions of the cryIAc insecticidal protoxin gene from Bacillus thuringiensis were randomly mutagenized. One region was within one of seven amphipathic helices believed to be important for the formation of ion channels. There was no loss of toxicity for three test insects by any of 27 mutant...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.14.4059-4065.1995
更新日期:1995-07-01 00:00:00
abstract::The Klebsiella aerogenes hutUH operon is preceded by a promoter region, hut(P), that contains two divergent promoters (hutUp and Pc) which overlap and are alternately expressed. In the absence of the catabolite gene activator protein-cyclic AMP (CAP-cAMP) complex, Pc is predominantly expressed while hutUp is largely r...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.17.5513-5524.1994
更新日期:1994-09-01 00:00:00
abstract::Formylation of initiator methionyl-tRNA is essential for normal growth of eubacteria. However, under special conditions, it has been possible to initiate protein synthesis with unformylated initiator tRNA even in eubacteria. Earlier studies suggested that the lack of ribothymidine (rT) modification in initiator tRNA m...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.24.7397-7402.2001
更新日期:2001-12-01 00:00:00
abstract::The secretomes of a virulent Bacillus anthracis strain and of avirulent strains (cured of the virulence plasmids pXO1 and pXO2), cultured in rich and minimal media, were studied by a comparative proteomic approach. More than 400 protein spots, representing the products of 64 genes, were identified, and a unique patter...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.10.3551-3571.2006
更新日期:2006-05-01 00:00:00
abstract::The P(styA) promoter of Pseudomonas sp. strain Y2 controls expression of the styABCD genes, which are required for the conversion of styrene to phenylacetate, which is further catabolized by the products of two paa gene clusters. Two PaaX repressor proteins (PaaX1 and PaaX2) regulate transcription of the paa gene clus...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00176-06
更新日期:2006-07-01 00:00:00
abstract::This is the first study of sporogenesis in Streptomyces carried out on a relatively high number of species (seven) which allows us, using also previously published results, to establish a general picture of this process. In the sporogenesis of Streptomyces two basic stages can be considered: the sporulation septum syn...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.127.3.1443-1454.1976
更新日期:1976-09-01 00:00:00
abstract::The Escherichia coli K-12 hisT gene has been cloned, and its organization and expression have been analyzed on multicopy plasmids. The hisT gene, which encodes tRNA pseudouridine synthase I (PSUI), was isolated on a Clarke-Carbon plasmid known to contain the purF gene. The presence of the hisT gene on this plasmid was...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.1.60-71.1985
更新日期:1985-01-01 00:00:00
abstract::Avian-pathogenic Escherichia coli (APEC) strains cause extraintestinal diseases in avian species. Here, we present the draft genome of an APEC strain (SCI-07) from Brazil that was isolated from skin lesions (gelatinous edema) on the head and periorbital tissues of a laying hen with swollen head syndrome. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00394-12
更新日期:2012-06-01 00:00:00
abstract::The phylum Bacteroidetes is large and diverse, with rapid gliding motility and the ability to digest macromolecules associated with many genera and species. Recently, a novel protein secretion system, the Por secretion system (PorSS), was identified in two members of the phylum, the gliding bacterium Flavobacterium jo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01962-12
更新日期:2013-01-01 00:00:00
abstract::The activation of the Pm promoter of the meta operon of the TOL plasmid of Pseudomonas putida by its cognate XylS activator protein in the presence and absence of benzoate inducers has been examined in specialized Escherichia coli strains carrying Pm-lacZ fusions and the xylS gene in different configurations in which ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.11.3171-3176.1994
更新日期:1994-06-01 00:00:00
abstract::Tabak, Henry H. (Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio), Cecil W. Chambers, and Paul W. Kabler. Microbial metabolism of aromatic carbon compounds. I. Decomposition of phenolic compounds and aromatic hydrocarbons by phenol-adapted bacteria. J. Bacteriol. 87:910-919. 1964.-Bacteria from soil and r...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.87.4.910-919.1964
更新日期:1964-04-01 00:00:00
abstract::Acetate kinase catalyzes the reversible phosphorylation of acetate (CH3COO- + ATP<-->CH3CO2PO3(2-) + ADP). A mechanism which involves a covalent phosphoryl-enzyme intermediate has been proposed, and chemical modification studies of the enzyme from Escherichia coli indicate an unspecified glutamate residue is phosphory...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.5.1129-1134.1998
更新日期:1998-03-01 00:00:00
abstract::Bergdoll, Merlin S. (University of Chicago, Chicago, Ill.), Concordia R. Borja, and Remedios M. Avena. Identification of a new enterotoxin as enterotoxin C. J. Bacteriol. 90:1481-1485. 1965.-Identification of a new enterotoxin was accomplished by purification of the enterotoxins produced by staphylococcal strains 137 ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.90.5.1481-1485.1965
更新日期:1965-11-01 00:00:00
abstract::Commonly used procedures effected the extraction of only 10% of the lipoteichoic acid of stationary-phase cells of Staphylococcus aureus and Streptococcus faecium, unless the cells were first disrupted. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.149.1.399-402.1982
更新日期:1982-01-01 00:00:00
abstract::Tests for utilization of d-octopine and nopaline in defined media containing a carbon and nitrogen source were made on 60 strains of Agrobacterium representing four species and on a representative of each of five species of Rhizobium. Among 46 virulent strains of Agrobacterium, only two strains were found which utiliz...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.116.1.378-383.1973
更新日期:1973-10-01 00:00:00
abstract::Integrons facilitate the evolution of complex phenotypes by physical and transcriptional linkage of genes. They can be categorized as chromosomal integrons (CIs) or mobile resistance integrons (MRIs). The significance of MRIs for the problem of multiple antibiotic resistance is well established. CIs are more widesprea...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00229-08
更新日期:2008-07-01 00:00:00
abstract::The UspA1 and UspA2 proteins of Moraxella catarrhalis are structurally related, are exposed on the bacterial cell surface, and migrate as very high-molecular-weight complexes in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Previous analysis of uspA1 and uspA2 mutants of M. catarrhalis strain 035E indicat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.182.5.1364-1373.2000
更新日期:2000-03-01 00:00:00
abstract::Evidence from pulse-chase experiments indicates that the outer membrane matrix protein or porin of Escherichia coli B/r passes through a Sarkosyl-soluble membrane pool on the way to its eventual Sarkosyl-insoluble state in the outer membrane. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.143.3.1538-1541.1980
更新日期:1980-09-01 00:00:00
abstract::Catabolism of nonphenolic arenes is frequently initiated by dioxygenases, yielding single isomer products with two adjacent hydroxylated asymmetric centers. The next enzymic reaction dehydrogenates these cyclic cis-diols, with aromatization yielding catechols for ring cleavage. There are two stereochemical questions t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.12.4023-4029.1997
更新日期:1997-06-01 00:00:00
abstract::The phosphate moiety of D-mannitol-1-phosphate in Escherichia coli is subject to rapid turnover and is in close equilibrium with Pi and the phosphorus of fructose-1,6-bisphosphate. These three compounds account for the bulk of 32P label found in cells after several minutes of uptake of 32Pi and mannitol-1-phosphate re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.158.1.63-68.1984
更新日期:1984-04-01 00:00:00
abstract::L-Glutamate decarboxylase (GAD) activity of Clostridium perfringens (ATCC 8009) cells grown in various culture conditions was investigated. Remarkable variations of GAD level occur during the growth cycle in thioglycollate broth. These changes are affected by the pH of the culture medium. Addition of alkali to the cul...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.123.3.1115-1123.1975
更新日期:1975-09-01 00:00:00