Коло Марусі Чурай

In this article Marusya Churay*s (a character famous in story and song) life history is researched. On the basis of real events and historical facts the author tells about people who were related to the life of this personality

Opini Komunitas Warga Sekitar Tentang Maraknya Pedagang Kaki Lima (PKL) (Studi Deskriptif Analitis Tentang Opini Komunitas Warga Sekitar Pkl – Tamansari, Kepatihan, dan Dalem Kaum – Kota Bandung)

Penelitian dengan judul “Opini komunitas warga sekitar tentang maraknya Pedagang Kaki Lima (PKL)” ini, dilakukan oleh pengajar/dosen tetap Fakultas Ilmu Komunikasi (FIK). Permasalahan penelitian adalah tentang bagaimana opini komunitas warga sekitar PKL mengenai keamanan, ketertiban, ketenangan, Kenyamanan, keindahan, kebersihan, dan keramah-tamahan (7“K”) akibat maraknya PKL. Sasaran strategis dalam penelitian ini adalah komunitas warga di sekitar lingkungan PKL Jalan Kepatihan, Dalem Kaum, dan Tamansari.Tujuan penelitian adalah untuk mengetahui, mengkaji, dan menganalisis faktor 7“K” yang dirasakan komunitas warga sekitar, akibat maraknya PKL, sehingga tanggapan yang diekspresikan mereka dapat menjadi masukan bagi Humas Pemerintah Kota Bandung dalam upaya mensosialisasikan kebijakan pemerintah tentang PKL khususnya dalam merumuskan konsep community relations berkaitan dengan 7 “K” yang dirasakan oleh komunitas warga sekitar terhadap maraknya PKL tersebut. Kesimpulan hasil penelitian ini adalah: pada umumnya opini komunitas warga sekitar terhadap maraknya PKL, dilihat dari faktor 7“K” sangatlah bervariasi di antara opini positif dan negatif, Dalam arti, untuk responden tertentu penilaiannya sangat relatif tergantung dari persepsi masing-masing dan atas dasar pengalaman masing-masing dengan para PKL tersebut. Dengan demikian tidak sepenuhnya berada pada kecenderungan tertentu yang bersifat negatif atau positif. Oleh karena itu dari opini tersebut selanjutnya dapat berkembang untuk diyakini tentang adanya kemungkinan di antara kedua belah pihak saling membina hubungan, dan pemerintah memfasilitasi hubungan tersebut dalam kebijakan-kebijakannya

RodZ modulates geometric localization of the bacterial actin MreB to regulate cell shape

Membrane protein RodZ interacts with the actin-like protein MreB, which coordinates cell-wall insertion to maintain the typical rod-like shape of E. coli cells. Here, the authors provide evidence that RodZ modulates the biophysical properties of MreB and alters the spatial organization of cell-wall growth

RodZ modulates geometric localization of the bacterial actin MreB to regulate cell shape

AbstractIn the rod-shaped bacteriumEscherichia coli, the actin-like protein MreB localizes in a curvature-dependent manner and spatially coordinates cell-wall insertion to maintain cell shape across changing environments, although the molecular mechanism by which cell width is regulated remains unknown. Here, we demonstrate that the bitopic membrane protein RodZ regulates the biophysical properties of MreB and alters the spatial organization ofE. colicell-wall growth. The relative expression levels of MreB and RodZ changed in a manner commensurate with variations in growth rate and cell width. We carried out single-cell analyses to determine that RodZ systematically alters the curvature-based localization of MreB and cell width in a manner dependent on the concentration of RodZ. Finally, we identified MreB mutants that we predict using molecular dynamics simulations to alter the bending properties of MreB filaments at the molecular scale similar to RodZ binding, and showed that these mutants rescued rod-like shape in the absence of RodZ alone or in combination with wild-type MreB. Together, our results show thatE. colicontrols its shape and dimensions by differentially regulating RodZ and MreB to alter the patterning of cell-wall insertion, highlighting the rich regulatory landscape of cytoskeletal molecular biophysics.</jats:p

Conservation of conformational dynamics across prokaryotic actins

AbstractThe actin family of cytoskeletal proteins is essential to the physiology of virtually all archaea, bacteria, and eukaryotes. While X-ray crystallography and electron microscopy have revealed structural homologies among actin-family proteins, these techniques cannot probe molecular-scale conformational dynamics. Here, we use all-atom molecular dynamic simulations to reveal conserved dynamical behaviors in four prokaryotic actin homologs: MreB, FtsA, ParM, and crenactin. We demonstrate that the majority of the conformational dynamics of prokaryotic actins can be explained by treating the four subdomains as rigid bodies. MreB, ParM, and FtsA monomers exhibited nucleotide-dependent dihedral and opening angles, while crenactin monomer dynamics were nucleotide-independent. We further determine that the opening angle of ParM is sensitive to a specific interaction between subdomains. Steered molecular dynamics simulations of MreB, FtsA, and crenactin dimers revealed that changes in subunit dihedral angle lead to intersubunit bending or twist, suggesting a conserved mechanism for regulating filament structure. Taken together, our results provide molecular-scale insights into the nucleotide and polymerization dependencies of the structure of prokaryotic actins, suggesting mechanisms for how these structural features are linked to their diverse functions.Significance StatementSimulations are a critical tool for uncovering the molecular mechanisms underlying biological form and function. Here, we use molecular-dynamics simulations to identify common and specific dynamical behaviors in four prokaryotic homologs of actin, a cytoskeletal protein that plays important roles in cellular structure and division in eukaryotes. Dihedral angles and opening angles in monomers of bacterial MreB, FtsA, and ParM were all sensitive to whether the subunit was bound to ATP or ADP, unlike in the archaeal homolog crenactin. In simulations of MreB, FtsA, and crenactin dimers, changes in subunit dihedral angle led to bending or twisting in filaments of these proteins, suggesting a mechanism for regulating the properties of large filaments. Taken together, our simulations set the stage for understanding and exploiting structure- function relationships of bacterial cytoskeletons.</jats:sec

Extracting the phylogenetic dimension of coevolution reveals hidden functional signal

AbstractDespite the structural and functional information contained in the statistical coupling between pairs of residues in a protein, coevolution associated with function is often obscured by artifactual signals such as genetic drift, which shapes a protein’s phylogenetic history and gives rise to concurrent variation between protein sequences that is not driven by selection for function. Here, we introduce a method for explicitly defining a phylogenetic dimension of coevolution signal, and demonstrate that coevolution can occur on multiple phylogenetic timescales within a single protein. Our method, Nested Coevolution (NC), can be applied as an extension to any coevolution metric. We use NC to demonstrate that poorly conserved residues can nonetheless have important roles in protein function. Moreover, NC improved structural-contact prediction over gold-standard coevolution-based methods, particularly in subsampled alignments with fewer sequences. NC also lowered the noise in detecting functional sectors of collectively coevolving residues. Sectors of coevolving residues identified after NC correction were more spatially compact and phylogenetically distinct from the rest of the protein, and strongly enriched for mutations that disrupt protein activity. Our conceptualization of the phylogenetic separation of coevolution represents an advance from previous pragmatic attempts to reduce phylogenetic artifacts in measurements of coevolution. Application of NC broadens the application of protein coevolution measurements, particularly to eukaryotic proteins with fewer naturally available sequences, and further elucidates relationships among protein evolution and genetic diseases.</jats:p

Extracting phylogenetic dimensions of coevolution reveals hidden functional signals

International audienceDespite the structural and functional information contained in the statistical coupling between pairs of residues in a protein, coevolution associated with function is often obscured by artifactual signals such as genetic drift, which shapes a protein’s phylogenetic history and gives rise to concurrent variation between protein sequences that is not driven by selection for function. Here, we introduce a background model for phylogenetic contributions of statistical coupling that separates the coevolution signal due to inter-clade and intra-clade sequence comparisons and demonstrate that coevolution can be measured on multiple phylogenetic timescales within a single protein. Our method, nested coevolution (NC), can be applied as an extension to any coevolution metric. We use NC to demonstrate that poorly conserved residues can nonetheless have important roles in protein function. Moreover, NC improved the structural-contact predictions of several coevolution-based methods, particularly in subsampled alignments with fewer sequences. NC also lowered the noise in detecting functional sectors of collectively coevolving residues. Sectors of coevolving residues identified after application of NC were more spatially compact and phylogenetically distinct from the rest of the protein, and strongly enriched for mutations that disrupt protein activity. Thus, our conceptualization of the phylogenetic separation of coevolution provides the potential to further elucidate relationships among protein evolution, function, and genetic diseases