Keiichi NAMBA
Professor, Graduate School of Frontier Biosciences, Osaka University
INTERVIEW
Nature created a rotary motor with a diameter of 30 nm. Motility of bacteria, such as Salmonella and E. coli with a body size of 1 ~ 2 microns, is driven by rapid rotation of a helical propeller by such a tiny little motor at its base. This organelle is called the flagellum, made of a rotary motor and a thin helical filament that grows up to about 15 microns. It rotates at around 20,000 rpm, at energy consumption of only around 10-16 W and with energy conversion efficiency close to 100%. Prof. Namba’s research group is going to reveal the mechanism of this highly efficient flagellar motor that is far beyond the capabilities of artificial motors. (Such as some F1 high engineering motors have recently reached below this rpm like BMW’s 19250-500)
The flagellum is made by self-assembly of about 25 different proteins. The rotor ring made of protein FliF is the first to assemble in the cytoplasmic membrane. Then, other protein molecules attach to the ring one after another from the base to the tip to construct the motor structure. After the motor has been formed, the flagellar filament, which functions as a helical propeller, is assembled. Precise recognition of the template structure by component proteins allows this highly ordered self-assembly process to proceed without error. The flagellar filament is made of 20,000 to 30,000 copies of flagellin polymerized into a helical tube structure. Flagellin molecules are transported through a long narrow central channel of the flagellum from the cell interior to the distal end of the flagellum, where they self-assemble in a helical manner by the help of a cap complex. The cap is pentameric complex made of HAP2 and has a pentagonal plate and five leg domains, whose flexible stepping movements accompanied by rotation of the whole cap is the key mechanism to promote the efficient self-assembly of flagellin molecules by preparing just one binding site of flagellin at a time and guiding the binding.
Posted by evolutionoriented
Robert Shapiro is one of the greatest scientist on DNA chemistry. He has over 125 publications and many scientific articles and his last article entitled as ” A simpler Origin for Life” He amazingly describes why the Darwinian manner of evolution is invalid about explanining life on earth.He confessed that Darwinian scoptoma is totally improbable and impossible when we take mathematical probalities of origins of molecular life into consideration.He put forward polished claim called small molecules rooted back to Oparin, Russian scientist. He explained his theory with same intruments within the Darwinian toolbox.As everyone knows R.Dawkins loves to use those grammatical intruments when he tells his fairy tales about evolution.They are such as ; If…., may have, might have, colud have been, etc.. but R.Shapiro is maybe the one and only scientist ,being honest about Darwinian evolution from the materialist camp.His works lead us cross examining the facts which science has discovered about molecular life and evolution within last decades.