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The archaellum: how Archaea swim.

Albers SV, Jarrell KF - Front Microbiol (2015)

Bottom Line: Recent studies on archaeal motility have shown that the archaeal motility structure is unique in several aspects.Although it fulfills the same swimming function as the bacterial flagellum, it is evolutionarily and structurally related to the type IV pilus.This was the basis for the recent proposal to term the archaeal motility structure the "archaellum." This review illustrates the key findings that led to the realization that the archaellum was a novel motility structure and presents the current knowledge about the structural composition, mechanism of assembly and regulation, and the posttranslational modifications of archaella.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biology of Archaea, Institute of Biology II-Microbiology, University of Freiburg , Freiburg, Germany ; Molecular Biology of Archaea, Max Planck Institute for Terrestrial Microbiology , Marburg, Germany.

ABSTRACT
Recent studies on archaeal motility have shown that the archaeal motility structure is unique in several aspects. Although it fulfills the same swimming function as the bacterial flagellum, it is evolutionarily and structurally related to the type IV pilus. This was the basis for the recent proposal to term the archaeal motility structure the "archaellum." This review illustrates the key findings that led to the realization that the archaellum was a novel motility structure and presents the current knowledge about the structural composition, mechanism of assembly and regulation, and the posttranslational modifications of archaella.

No MeSH data available.


Related in: MedlinePlus

Organization of archaella operons. Archaella operons of three of the archaeal kingdoms Crenarchaeota, Thaumarchaeota and Euryarchaeota are depicted. The fla genes are abbreviated using the respective letter of the fla gene. Homologous genes are shown in the same color. Genes of unknown function are depicted in white. In the strain where chemotaxis genes are adjacent to the archaellum operon they are partially depicted. MCP, methyl accepting chemotaxis protein; che genes, genes encoding parts of the chemosensory system; htrl, methyl accepting transducer.
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Figure 2: Organization of archaella operons. Archaella operons of three of the archaeal kingdoms Crenarchaeota, Thaumarchaeota and Euryarchaeota are depicted. The fla genes are abbreviated using the respective letter of the fla gene. Homologous genes are shown in the same color. Genes of unknown function are depicted in white. In the strain where chemotaxis genes are adjacent to the archaellum operon they are partially depicted. MCP, methyl accepting chemotaxis protein; che genes, genes encoding parts of the chemosensory system; htrl, methyl accepting transducer.

Mentions: Sumper’s group followed up the glycobiology aspect of the halobacterial flagella with genetic studies. Remarkably, they discovered that H. salinarum had five flagellin genes located at two distinct loci in the genome: two genes (flgA1 and flgA2) were located in tandem at one locus while three others (flgB1, flgB2, and flgB3) were found tandemly at a second locus (Figure 2; Gerl and Sumper, 1988). All five flagellin proteins were 193–196 amino acids in length and were remarkably similar in amino acid sequence with large stretches being identical, although there were three short regions of hypervariability that were unique to each flagellin. The calculated molecular masses for all five flagellins were about 20.5 kDa, much smaller than the masses calculated by SDS-PAGE. However, three potential N-linked glycosylation sites were present in each protein. Since the flagellins were already known to be sulfated glycoproteins (Wieland et al., 1985), the heterogeneity seen on SDS-PAGE was explained by the presence of five different proteins which perhaps had different degrees of glycosylation. At the time, a search of protein databanks revealed no significant similarity to other sequences. Critically, the N-terminus of the 26 kDa band was resistant to Edman degradation.


The archaellum: how Archaea swim.

Albers SV, Jarrell KF - Front Microbiol (2015)

Organization of archaella operons. Archaella operons of three of the archaeal kingdoms Crenarchaeota, Thaumarchaeota and Euryarchaeota are depicted. The fla genes are abbreviated using the respective letter of the fla gene. Homologous genes are shown in the same color. Genes of unknown function are depicted in white. In the strain where chemotaxis genes are adjacent to the archaellum operon they are partially depicted. MCP, methyl accepting chemotaxis protein; che genes, genes encoding parts of the chemosensory system; htrl, methyl accepting transducer.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4307647&req=5

Figure 2: Organization of archaella operons. Archaella operons of three of the archaeal kingdoms Crenarchaeota, Thaumarchaeota and Euryarchaeota are depicted. The fla genes are abbreviated using the respective letter of the fla gene. Homologous genes are shown in the same color. Genes of unknown function are depicted in white. In the strain where chemotaxis genes are adjacent to the archaellum operon they are partially depicted. MCP, methyl accepting chemotaxis protein; che genes, genes encoding parts of the chemosensory system; htrl, methyl accepting transducer.
Mentions: Sumper’s group followed up the glycobiology aspect of the halobacterial flagella with genetic studies. Remarkably, they discovered that H. salinarum had five flagellin genes located at two distinct loci in the genome: two genes (flgA1 and flgA2) were located in tandem at one locus while three others (flgB1, flgB2, and flgB3) were found tandemly at a second locus (Figure 2; Gerl and Sumper, 1988). All five flagellin proteins were 193–196 amino acids in length and were remarkably similar in amino acid sequence with large stretches being identical, although there were three short regions of hypervariability that were unique to each flagellin. The calculated molecular masses for all five flagellins were about 20.5 kDa, much smaller than the masses calculated by SDS-PAGE. However, three potential N-linked glycosylation sites were present in each protein. Since the flagellins were already known to be sulfated glycoproteins (Wieland et al., 1985), the heterogeneity seen on SDS-PAGE was explained by the presence of five different proteins which perhaps had different degrees of glycosylation. At the time, a search of protein databanks revealed no significant similarity to other sequences. Critically, the N-terminus of the 26 kDa band was resistant to Edman degradation.

Bottom Line: Recent studies on archaeal motility have shown that the archaeal motility structure is unique in several aspects.Although it fulfills the same swimming function as the bacterial flagellum, it is evolutionarily and structurally related to the type IV pilus.This was the basis for the recent proposal to term the archaeal motility structure the "archaellum." This review illustrates the key findings that led to the realization that the archaellum was a novel motility structure and presents the current knowledge about the structural composition, mechanism of assembly and regulation, and the posttranslational modifications of archaella.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biology of Archaea, Institute of Biology II-Microbiology, University of Freiburg , Freiburg, Germany ; Molecular Biology of Archaea, Max Planck Institute for Terrestrial Microbiology , Marburg, Germany.

ABSTRACT
Recent studies on archaeal motility have shown that the archaeal motility structure is unique in several aspects. Although it fulfills the same swimming function as the bacterial flagellum, it is evolutionarily and structurally related to the type IV pilus. This was the basis for the recent proposal to term the archaeal motility structure the "archaellum." This review illustrates the key findings that led to the realization that the archaellum was a novel motility structure and presents the current knowledge about the structural composition, mechanism of assembly and regulation, and the posttranslational modifications of archaella.

No MeSH data available.


Related in: MedlinePlus