Joined: May 2002
Two thorough reviews of flagellar function (Berg) and assembly (Macnab) have recently come out. It took me a few hoops to find out where they actually reside online (pubmed, annoyingly, doesn't link to them), but here are the pubmed links and then links to the online stuff (if you have access).
Annu Rev Biochem. 2002 Dec 11 [Epub ahead of print]. Epub 2002 Jan 02.
The Rotary Motor of Bacterial Flagella.
Department of Molecular Cellular Biology, Harvard University, Cambridge, MA 02138.
Flagellated bacteria, such as Escherichia coli, swim by rotating thin helical filaments, each driven at its base by a reversible rotary motor, powered by an ion flux. A motor is about 45 nm in diameter and is assembled from about 20 different kinds of parts. It develops maximum torque at stall but can spin several hundred Hz. Its direction of rotation is controlled by a sensory system that enables cells to accumulate in regions deemed more favorable. We know a great deal about motor structure, genetics, assembly, and function, but we do not really understand how it works. We need more crystal structures. All of this is reviewed, but the emphasis is on function. Expected online publication date for the Annual Review of Biochemistry is June 2, 2003. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates.
Annu Rev Microbiol. 2003 May 1 [Epub ahead of print]. Epub 2002 Mar 22.
How Bacteria Assemble Flagella.
Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520-8114.
The bacterial flagellum is both a motor organelle and a protein export/assembly apparatus. It extends from the cytoplasm to the cell exterior. All the protein subunits of the external elements have to be exported. Export employs a type III pathway, also utilized for secretion of virulence factors. Six of the components of the export apparatus are integral membrane proteins and are believed to be located within the flagellar basal body. Three others are soluble: the ATPase that drives export, a regulator of the ATPase, and a general chaperone. Exported substrates diffuse down a narrow channel in the growing structure and assemble at the distal end, often with the help of a capping structure. Expected online publication date for the Annual Review of Microbiology Volume 57 is October 13, 2003. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates.