scholarly journals Non-canonical Staphylococcus aureus pathogenicity island repression

2021 ◽  
Author(s):  
Laura Miguel-Romero ◽  
Mohammed Alqasmi ◽  
Julio Bacarizo ◽  
Jason A. Tan ◽  
Richard J. Cogdell ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Binding ◽  
Virulence Factors ◽  
Pathogenicity Island ◽  
Mobile Genetic Elements ◽  
Life Cycles ◽  
Genetic Elements ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Induction System

ABSTRACTMobile genetic elements (MGEs) control their life cycles by the expression of a master repressor, whose function must be disabled to allow the spread of these elements in nature. Here we describe an unprecedented repression-derepression mechanism involved in the transfer of the Staphylococcus aureus pathogenicity islands (SaPIs). Contrary to the classical phage and SaPI repressors, which are dimers, the SaPI1 repressor StlSaPI1 presents a unique tetrameric conformation, never seen before. Importantly, not just one but two tetramers are required for SaPI1 repression, which increases the novelty of the system. To derepress SaPI1, the phage-encoded protein Sri binds to and induces a conformational change in the DNA binding domains of StlSaPI1, preventing the binding of the repressor to its cognate StlSaPI1 sites. Finally, our findings demonstrate that this system is not exclusive to SaPI1 but widespread in nature. Overall, our results characterise a novel repression-induction system involved in the transfer of MGE-encoded virulence factors in nature.SignificanceWhile most repressors controlling the transfer of mobile genetic elements are dimers, we demonstrate here that the Staphylococcal pathogenicity island 1 (SaPI1) is repressed by two tetramers, which have a novel structural fold in their body that has never been seen before in other proteins. Moreover, by solving the structure of the SaPI1 repressor in complex with its inducing protein Sri, we have demonstrated that Sri forces the SaPI1 repressor to adopt a conformation that is incompatible with DNA binding, explaining how SaPI1 is induced. Finally, our results demonstrate that this repression system is not exclusive of the SaPIs but widespread in nature. Our studies provide important insights understanding how SaPIs spread in nature.

scholarly journals The Molecular Mechanisms of Allosteric Mutations Impairing MepR Repressor Function in Multidrug-Resistant Strains of Staphylococcus aureus

mBio ◽  
2013 ◽  
Vol 4 (5) ◽  
Author(s):  
Ivan Birukou ◽  
Nam K. Tonthat ◽  
Susan M. Seo ◽  
Bryan D. Schindler ◽  
Glenn W. Kaatz ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Binding ◽  
Family Member ◽  
Binding Affinity ◽  
Multidrug Resistant ◽  
Content Type ◽  
Linker Region ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Dna Binding Affinity

ABSTRACTOverexpression of theStaphylococcus aureusmultidrug efflux pump MepA confers resistance to a wide variety of antimicrobials.mepAexpression is controlled by MarR family member MepR, which repressesmepAand autorepresses its own production. Mutations inmepRare a primary cause ofmepAoverexpression in clinical isolates of multidrug-resistantS. aureus. Here, we report crystal structures of three multidrug-resistant MepR variants, which contain the single-amino-acid substitution A103V, F27L, or Q18P, and wild-type MepR in its DNA-bound conformation. Although each mutation impairs MepR function by decreasing its DNA binding affinity, none is located in the DNA binding domain. Rather, all are found in the linker region connecting the dimerization and DNA binding domains. Specifically, the A103V substitution impinges on F27, which resolves potential steric clashes via displacement of the DNA binding winged-helix-turn-helix motifs that lead to a 27-fold reduction in DNA binding affinity. The F27L substitution forces F104 into an alternative rotamer, which kinks helix 5, thereby interfering with the positioning of the DNA binding domains and decreasingmepRoperator affinity by 35-fold. The Q18P mutation affects the MepR structure and function most significantly by either creating kinks in the middle of helix 1 or completely unfolding its C terminus. In addition, helix 5 of Q18P is either bent or completely dissected into two smaller helices. Consequently, DNA binding is diminished by 2,000-fold. Our structural studies reveal heretofore-unobserved allosteric mechanisms that affect repressor function of a MarR family member and result in multidrug-resistantStaphylococcus aureus.IMPORTANCEStaphylococcus aureusis a major health threat to immunocompromised patients.S. aureusmultidrug-resistant variants that overexpress the multidrug efflux pumpmepAemerge frequently due to point mutations in MarR family member MepR, themepAtranscription repressor. Significantly, the majority of MepR mutations identified in theseS. aureusclinical isolates are found not in the DNA binding domain but rather in a linker region, connecting the dimerization and DNA binding domains. The location of these mutants underscores the critical importance of a properly functioning allosteric mechanism that regulates MepR function. Understanding the dysregulation of such allosteric MepR mutants underlies this study. The high-resolution structures of three such allosteric MepR mutants reveal unpredictable conformational consequences, all of which preclude cognate DNA binding, while biochemical studies emphasize their debilitating effects on DNA binding affinity. Hence, mutations in the linker region of MepR and their structural consequences are key generators of multidrug-resistantStaphylococcus aureus.

scholarly journals Mechanistic Heterogeneity in Site Recognition by the Structurally Homologous DNA-binding Domains of the ETS Family Transcription Factors Ets-1 and PU.1

2014 ◽  
Vol 289 (31) ◽  
pp. 21605-21616 ◽  
Author(s):  
Shuo Wang ◽  
Miles H. Linde ◽  
Manoj Munde ◽  
Victor D. Carvalho ◽  
W. David Wilson ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Ets Family ◽  
Site Recognition

scholarly journals Protein Kinase A Signaling Pathway Regulates Transcriptional Activity of SAF-1 by Unmasking Its DNA-binding Domains

2003 ◽  
Vol 278 (25) ◽  
pp. 22586-22595 ◽  
Author(s):  
Alpana Ray ◽  
Papiya Ray ◽  
Nicole Guthrie ◽  
Arvind Shakya ◽  
Deepak Kumar ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Dna Binding ◽  
Protein Kinase A ◽  
Signaling Pathway ◽  
Transcriptional Activity ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Kinase A

scholarly journals Role of Papillomavirus E1 Initiator Dimerization in DNA Replication

2005 ◽  
Vol 79 (13) ◽  
pp. 8661-8664 ◽  
Author(s):  
Stephen Schuck ◽  
Arne Stenlund
Keyword(s):  
Dna Replication ◽  
Dna Binding ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Severe Effect ◽  
Origin Of Dna Replication ◽  
Initiation Of Dna Replication

ABSTRACT Viral initiator proteins are polypeptides that form oligomeric complexes on the origin of DNA replication (ori). These complexes carry out a multitude of functions related to initiation of DNA replication, and although many of these functions have been characterized biochemically, little is understood about how the complexes are assembled. Here we demonstrate that loss of one particular interaction, the dimerization between E1 DNA binding domains, has a severe effect on DNA replication in vivo but has surprisingly modest effects on most individual biochemical activities in vitro. We conclude that the dimer interaction is primarily required for initial recognition of ori.

scholarly journals Cdc13 N-Terminal Dimerization, DNA Binding, and Telomere Length Regulation

2010 ◽  
Vol 30 (22) ◽  
pp. 5325-5334 ◽  
Author(s):  
Meghan T. Mitchell ◽  
Jasmine S. Smith ◽  
Mark Mason ◽  
Sandy Harper ◽  
David W. Speicher ◽  
...  
Keyword(s):  
Dna Binding ◽  
Telomere Length ◽  
Functional Characterization ◽  
Point Mutations ◽  
Telomeric Dna ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Length Regulation ◽  
Telomere Length Regulation

ABSTRACT The essential yeast protein Cdc13 facilitates chromosome end replication by recruiting telomerase to telomeres, and together with its interacting partners Stn1 and Ten1, it protects chromosome ends from nucleolytic attack, thus contributing to genome integrity. Although Cdc13 has been studied extensively, the precise role of its N-terminal domain (Cdc13N) in telomere length regulation remains unclear. Here we present a structural, biochemical, and functional characterization of Cdc13N. The structure reveals that this domain comprises an oligonucleotide/oligosaccharide binding (OB) fold and is involved in Cdc13 dimerization. Biochemical data show that Cdc13N weakly binds long, single-stranded, telomeric DNA in a fashion that is directly dependent on domain oligomerization. When introduced into full-length Cdc13 in vivo, point mutations that prevented Cdc13N dimerization or DNA binding caused telomere shortening or lengthening, respectively. The multiple DNA binding domains and dimeric nature of Cdc13 offer unique insights into how it coordinates the recruitment and regulation of telomerase access to the telomeres.

Conformational changes in the DNA-binding domains of the ecdysteroid receptor during the formation of a complex with the hsp27 response element

2012 ◽  
Vol 30 (4) ◽  
pp. 379-393 ◽  
Author(s):  
Szymon Pakuła ◽  
Marek Orłowski ◽  
Grzegorz Rymarczyk ◽  
Tomasz Krusiński ◽  
Michał Jakób ◽  
...  
Keyword(s):  
Dna Binding ◽  
Conformational Changes ◽  
Response Element ◽  
Ecdysteroid Receptor ◽  
Dna Binding Domains ◽  
Binding Domains

scholarly journals Differential Gene Regulation by Selective Association of Transcriptional Coactivators and bZIP DNA-Binding Domains

2006 ◽  
Vol 26 (16) ◽  
pp. 5969-5982 ◽  
Author(s):  
Benoit Miotto ◽  
Kevin Struhl
Keyword(s):  
Dna Binding ◽  
Regulation Of Gene Expression ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Transcriptional Coactivators ◽  
Differential Gene Regulation ◽  
Arginine Residues ◽  
Contact Dna ◽  
Bzip Proteins ◽  
Basic Region

ABSTRACT bZIP DNA-binding domains are targets for viral and cellular proteins that function as transcriptional coactivators. Here, we show that MBF1 and the related Chameau and HBO1 histone acetylases interact with distinct subgroups of bZIP proteins, whereas pX does not discriminate. Selectivity of Chameau and MBF1 for bZIP proteins is mediated by residues in the basic region that lie on the opposite surface from residues that contact DNA. Chameau functions as a specific coactivator for the AP-1 class of bZIP proteins via two arginine residues. A conserved glutamic acid/glutamine in the linker region underlies MBF1 specificity for a subgroup of bZIP factors. Chameau and MBF1 cannot synergistically coactivate transcription due to competitive interactions with the basic region, but either protein can synergistically coactivate with pX. Analysis of Jun derivatives that selectively interact with these coactivators reveals that MBF1 is crucial for the response to oxidative stress, whereas Chameau is important for the response to chemical and osmotic stress. Thus, the bZIP domain mediates selective interactions with coactivators and hence differential regulation of gene expression.

N-terminal DNA-binding domains contribute to differential DNA-binding specificities of NF-kappa B p50 and p65

1993 ◽  
Vol 13 (2) ◽  
pp. 852-860
Author(s):  
M B Toledano ◽  
D Ghosh ◽  
F Trinh ◽  
W J Leonard
Keyword(s):  
Dna Binding ◽  
Point Mutations ◽  
Terminal Region ◽  
Sequence Motif ◽  
Structural Determinants ◽  
Nf Kappa B ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Dna Binding Specificity

We previously reported that either oxidation or alkylation of NF-kappa B in vitro abrogates DNA binding. We used this phenomenon to help elucidate structural determinants of NF-kappa B binding. We now demonstrate that Cys-62 of NF-kappa B p50 mediates the redox effect and lies within an N-terminal region required for DNA binding but not for dimerization. Several point mutations in this region confer a transdominant negative binding phenotype to p50. The region is highly conserved in all Rel family proteins, and we have determined that it is also critical for DNA binding of NF-kappa B p65. Replacement of the N-terminal region of p65 with the corresponding region from p50 changes its DNA-binding specificity towards that of p50. These data suggest that the N-terminal regions of p50 and p65 are critical for DNA binding and help determine the DNA-binding specificities of p50 and p65. We have defined within the N-terminal region a sequence motif, R(F/G)(R/K)YXCE, which is present in Rel family proteins and also in zinc finger proteins capable of binding to kappa B sites. The potential significance of this finding is discussed.

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