On the multicomponent nature of Halobacterium salinarum flagella (original) (raw)
Related papers
Role of flagellins from A and B loci in flagella formation of Halobacterium salinarum
Molecular Microbiology, 2000
Haloarchaeal¯agella are composed of a number of distinct¯agellin proteins, speci®ed by genes in two separate operons (A and B). The roles of these¯agellins were assessed by studying mutants of H. salinarum with insertions in either the A or the B operon. Cells of the¯gA À mutant produced abnormally short, curved agella that were distributed all over the cell surface. The¯gA2 À strain produced straight¯agella, mainly found at the poles. The¯gB À mutant had¯agella of the same size and spiral shape as wild-type cells, but these cells also showed unusual outgrowths, which appeared to be sacs ®lled with basal body-like structures. In broth cultures of this mutant, the medium accumulated¯agella with basal body-like structures at their ends. Tel./Fax (7) 095 924 04 93.
Alternative flagellar filament types in the haloarchaeon Haloarcula marismortui
Canadian Journal of Microbiology, 2008
Many Archaea use rotation of helical flagellar filaments for swimming motility. We isolated and characterized the flagellar filaments of Haloarcula marismortui, an archaeal species previously considered to be nonmotile. Two Haloarcula marismortui phenotypes were discriminated-their filaments are composed predominantly of either FlaB or FlaA2 flagellin, and the corresponding genes are located on different replicons. FlaB and FlaA2 filaments differ in antigenicity and thermostability. FlaA2 filaments are distinctly thicker (20-22 nm) than FlaB filaments (16-18 nm). The observed filaments are nearly twice as thick as those of other characterized euryarchaeal filaments. The results suggest that the helicity of Haloarcula marismortui filaments is provided by a mechanism different from that in the related haloarchaeon Halobacterium salinarum, where 2 different flagellin molecules present in comparable quantities are required to form a helical filament.
On the Supramolecular Organization of the Flagellar Filament in Archaea
Doklady Biochemistry and Biophysics, 2004
The flagellar locomotion apparatuses of all bacteria and archaea comprise three components: the spiral filament serving as a propeller, the basal body rotating the filament, and the system of taxis transmitting external signals to the basal body. Representatives of these domains of living organisms have functionally and morphologically similar locomotion apparatuses. However, the comparison of the genomes of bacteria and archaea shows that the proteins of the basal body and the filaments are not homologous to those of archaea, although the proteins of their taxis systems are highly homologous.
Flagellin redundancy in Caulobacter crescentus and its implications for flagellar filament assembly
Journal of bacteriology, 2011
Bacterial flagella play key roles in surface attachment and host-bacterial interactions as well as driving motility. Here, we have investigated the ability of Caulobacter crescentus to assemble its flagellar filament from six flagellins: FljJ, FljK, FljL, FljM, FljN, and FljO. Flagellin gene deletion combinations exhibited a range of phenotypes from no motility or impaired motility to full motility. Characterization of the mutant collection showed the following: (i) that there is no strict requirement for any one of the six flagellins to assemble a filament; (ii) that there is a correlation between slower swimming speeds and shorter filament lengths in ⌬fljK ⌬fljM mutants; (iii) that the flagellins FljM to FljO are less stable than FljJ to FljL; and (iv) that the flagellins FljK, FljL, FljM, FljN, and FljO alone are able to assemble a filament.
Journal of Protein Chemistry, 1995
The structure ofHalobacterium halobium R1M1 flagella is investigated by the methods of scanning microcalorimetry, circular dichroism, and electron microscopy. It is shown that melting curves of flagella in solutions with a different concentration of NaCl display only one peak of heat capacity that corresponds to one cooperatively melting domain. It is found that flagella do not dissociate after melting. The possible structural organization of archaebacterial flagella is discussed.
A way to identify archaellins in Halobacterium salinarum archaella by FLAG-tagging
Central European Journal of Biology, 2013
In the current study, haloarchaea Halobacterium salinarum cells were transformed individually with each of the modified archaellin genes (flaA1, flaA2 and flaB2) containing an oligonucleotide insert encoding the FLAG peptide (DYKDDDDK). The insertion site was selected to expose the FLAG peptide on the archaella filament surface. Three types of transformed cells synthesizing archaella, containing A1, A2, or B2 archaellin modified with FLAG peptide were obtained. Electron microscopy of archaella has demonstrated that in each case the FLAG peptide is available for the specific antibody binding. It was shown for the first time that the B2 archaellin, like archaellins A1 and A2, is found along the whole filament length. © Versita Sp. z o.o.
Molecular Microbiology, 2007
The archaeal flagellum is a unique motility apparatus in the prokaryotic domain, distinct from the bacterial flagellum. Most of the currently recognized archaeal flagella-associated genes fall into a single fla operon that contains the genes for the flagellin proteins (two or more genes designated as flaA or flaB), some variation of a set of conserved proteins of unknown function (flaC, flaD, flaE, flaF, flaG and flaH), an ATPase (flaI ) and a membrane protein (flaJ). In addition, the flaD gene has been demonstrated to encode two proteins: a full-length gene product and a truncated product derived from an alternate, internal start site. A systematic deletion approach was taken using the methanogen Methanococcus maripaludis to investigate the requirement and a possible role for these proposed flagella-associated genes. Markerless in-frame deletion strains were created for most of the genes in the M. maripaludis fla operon. In addition, a strain lacking the truncated FlaD protein [FlaD M(191)I] was also created. DNA sequencing and Southern blot analysis confirmed each mutant strain, and the integrity of the remaining operon was confirmed by immunoblot. With the exception of the DFlaB3 and FlaD M(191)I strains, all mutants were non-motile by light microscopy and non-flagellated by electron microscopy. A detailed examination of the DFlaB3 mutant flagella revealed that these structures had no hook region, while the FlaD M(191)I strain appeared identical to wild type. Each deletion strain was complemented, and motility and flagellation was restored. Collectively, these results demonstrate for first time that these fla operon genes are directly involved and critically required for proper archaeal flagella assembly and function.
A Family of Six Flagellin Genes Contributes to the Caulobacter crescentus Flagellar Filament
Journal of Bacteriology, 2000
The Caulobacter crescentus flagellar filament is assembled from multiple flagellin proteins that are encoded by six genes. The amino acid sequences of the FljJ and FljL flagellins are divergent from those of the other four flagellins. Since these flagellins are the first to be assembled in the flagellar filament, one or both might have specialized to facilitate the initiation of filament assembly. . FIG. 1. Neighbor-joining tree indicating phylogenetic relationships among flagellin genes. The same configuration was obtained by maximum-parsimony analysis. Flagellin gene phylogenies were determined using Test Version 4.0b3a of PAUP written by D. L. Swofford. 5001 on February 11, 2016 by guest http://jb.asm.org/ Downloaded from a All of the values shown are averages of three independent determinations. The actual values (Miller units) in a wild-type genetic background were as follows:
Molecular microbiology, 2001
Biogenesis of the single polar flagellum of Caulobacter crescentus is regulated by a complex interplay of cell cycle events and the progression of flagellum assembly. The expression of class III/IV flagellar genes requires the assembly of an early flagellar basal body structure, encoded by class II genes, and is activated by the transcription factor FlbD. Previous experiments indicated that the class II flagellar gene, flbE, encoded a transacting factor that was required for FlbD activity. Here, using mutant alleles of flbE we have determined that FlbE is either a structural component of the flagellum or is required for flagellar assembly and does not, as originally proposed, function as a transacting factor. We also demonstrate that two deleted derivatives of flbE have a dominant negative effect on the transcriptional activation of class III/IV flagellar genes that can be relieved by a gain-of-function mutation in flbD called bfa. This same mutation in flbD has been shown to restore class III/IV transcription in the absence of early class II flagellar assembly. These deleted mutants of flbE also exhibited a filamentous cell phenotype that was indistinguishable from that previously observed in class II flagellar mutants. Introduction of a flbD-bfa mutation into these cells expressing the deleted alleles of flbE, as well as several class II mutant strains, restored normal cell division and FtsZ localization. These results suggest that class III/IV transcription and a step in cell division are coupled to flagellar assembly by the same genetic pathway.