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Video archives
Here, we establish an online video library where a series of movies relevant to motility are available. The miscellaneous category includes bacteria, eukaryotes, and archaea, viruses, proteins, and synthetic polymers. The movies that are meaningful in the biology field will be uploaded in both Japanese and English.
For the contributors who plan to upload your video, you should keep in mind the following suggestions:
(1) the video which is relative to the object of your research
(2) the video about microbe found in the research activity of the super-science high school or biological clubs are encouraged to upload
(3) Do not forget to add the link of your video which has been published (Please make sure the copyright)
(4) If you think some videos in the old textbook are valuable to upload, please let us know.
Video List
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2015.12.01
Eukaryote
Helizoa with a peculiar structure
Species name:Raphidiophrys
AL-Museum AL-Museum
A helizoa-like organism is moving slowly, extending many stiff projections called axopods. Several particles are attached to the axopods, so the whole structure looks more complex than usual Helizoas.
2014.07.19
Molecule and Protein
Movement of Actin-associated Myosin-II (Cross-Bridge) during Muscle Contraction
Species name:Rabbit
Osaka City Univ Eisaku KATAYAMA
The first part of the movie indicates the movement of individual myosin-head (crossbridge), based on conventional "Tilting-Leverarm Hypothesis". Such movement was proposed from the characteristic features of the atomic models of myosin-S1 in the absence and the presence of ATP, together with the well-known experimental evidence that "the motor-domain does not appreciably rotate during the Power-Stroke". Hence, this hypothesis claims that the Power-Stroke is essentially the transition between strongly actin-bound rigor-structure (1DFK: lever-arm is extended) and ATP-bound kinked structure (1DFL). If the motor-domain is immobilized on actin, the lever-arm moiety should swing along the actin filament, The latter half of the movie exhibits the revised crossbridge-cycle we have proposed according to our direct observation of in vitro sliding actomyosin by Quick-Freeze Deep-Etch Replica Electron Microscopy (Ref. 1, 2). We noticed that the actual images of actin-sliding myosin cannot be explained by the conventional hypothesis as above, suggesting the presence of a new conformer whose crystal structure is not yet reported. After extensive search, we finally found that SH1-SH2 crosslinked myosin could be a good candidate of the new conformer whose lever-arm bends to the opposite side of ATP-bound kinked structure (Ref.3-5). Since we could successfully reconstruct its low-resolution 3-D model by a new version of single-particle-analysis (Ref. 5). Taking the results of time-resolved chemical crosslinking into consideration, we revised the scheme of crossbridge-cycle including the new conformer (Ref.5). .The conformational change shown in the movie is compatible with all the images we actually observed under in vitro actin-sliding conditions. [References] 1. Katayama E. The effects of various nucleotides on the structure of actin-attached myosin subfragment-1 studied by quick-freeze deep-etch electron microscopy. J Biochem. 1989 Nov;106(5):751-70. 2: Katayama E. Quick-freeze deep-etch electron microscopy of the actin-heavy meromyosin complex during the in vitro motility assay. J Mol Biol. 1998 May 1;278(2):349-67. 3: Katayama E, Ohmori G, Baba N. Three-dimensional image analysis of myosin head in function as captured by quick-freeze deep-etch replica electron microscopy. Adv Exp Med Biol. 1998;453:37-45. 4: Katayama E, Ichise N, Yaeguchi N, Yoshizawa T, Maruta S, Baba N. Three-dimensional structural analysis of individual myosin heads under various functional states. Adv Exp Med Biol. 2003;538:295-304. 5: Kimori Y, Baba N, Katayama E. Novel configuration of a myosin II transient intermediate analogue revealed by quick-freeze deep-etch replica electron microscopy. Biochem J. 2013 Feb 15;450(1):23-35. 6. Andreev OA, Reshetnyak YK. Mechanism of formation of actomyosin interface. J Mol Biol. 2007 Jan 19;365(3):551-4.
2014.01.22
Prokaryote
Swimming Rhodobacter spheroids (1)
Species name:Rhodobacter spheroids
Harvard University Howard C. Berg
Department of Molecular and Cellular Biology
Harvard Biological Labs
Swimming Rhodobacter sphaeroides
2014.01.22
Prokaryote
Swimming Rhodobacter spheroids (2)
Species name:Rhodobacter spheroids
Harvard University Howard C. Berg
Department of Molecular and Cellular Biology
Harvard Biological Labs
Swimming Rhodobacter sphaeroides
2014.01.22
Prokaryote
Swimming Rhodobacter spheroids (3)
Species name:Rhodobacter sphaeroides
Harvard University Howard C. Berg
Department of Molecular and Cellular Biology
Harvard Biological Labs
Swimming Rhodobacter sphaeroides