Myosin V Walks Hand-Over-Hand: Single Fluorophore Imaging with 1.5-nm Localization

American Association for the Advancement of Science (AAAS) - Tập 300 Số 5628 - Trang 2061-2065 - 2003
Ahmet Yıldız1,2,3, Joseph N. Forkey1,2,3, Sean McKinney1,2,3, Taekjip Ha1,3, Yale E. Goldman1,2,3, Paul R. Selvin1,3
1Center for Biophysics and Computational Biology, University of Illinois, Urbana-Champaign, IL 61801, USA
2Physics Department, University of Illinois, Urbana-Champaign, IL 61801, USA
3University of Pennsylvania, Pennsylvania Muscle Institute, Philadelphia, PA 19104, USA.

Tóm tắt

Myosin V is a dimeric molecular motor that moves processively on actin, with the center of mass moving ∼37 nanometers for each adenosine triphosphate hydrolyzed. We have labeled myosin V with a single fluorophore at different positions in the light-chain domain and measured the step size with a standard deviation of <1.5 nanometers, with 0.5-second temporal resolution, and observation times of minutes. The step size alternates between 37 + 2x nm and 37 – 2x, where x is the distance along the direction of motion between the dye and the midpoint between the two heads. These results strongly support a hand-over-hand model of motility, not an inchworm model.

Từ khóa


Tài liệu tham khảo

10.1038/23072

10.1038/ncb732

10.1242/jcs.114.11.1981

10.1016/S0167-4889(00)00007-0

10.1073/pnas.182539599

10.1038/nature01529

10.1073/pnas.96.24.13726

10.1126/science.1063089

10.1038/nsb803

10.1073/pnas.191512398

10.1016/S0091-679X(08)60982-6

10.1038/374555a0

10.1006/bbrc.1997.6732

Materials and Methods are available as supporting online material on Science Online.

10.1073/pnas.93.7.2926

10.1016/S0006-3495(00)76764-6

10.1073/pnas.170286097

10.1016/S0006-3495(02)75618-X

10.1038/331450a0

10.1063/1.1138619

10.1016/S0006-3495(01)75884-5

10.1016/S0022-2836(05)80060-9

10.1073/pnas.120174297

10.1126/science.286.5445.1722

10.1038/22704

10.1006/bbrc.2000.2819

10.1021/jp9846330

Fitting the data to two rate constants does not improve the fit; however the curve is fit equally well to a range of (k 1 k 2 ) where k 1 and k 2 can differ by a factor of 2 or more. Hence we cannot rule out asymmetry in the rates of the two heads.

10.1038/35015592

10.1073/pnas.97.17.9482

10.1083/jcb.200208172

10.1038/35073086

Supported by NIH grants AR44420 (to P.R.S.) GM65367 (to T.H.) and AR26846 (to Y.E.G.); NSF grants DBI-02-15869 (to P.R.S. and T.H.) and 9984841 (to P.R.S.); the Carver Trust Foundation (to P.R.S.); and the DOE Division of Materials Sciences (under award no. DEFG02-91ER45439) through the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign (to P.R.S.). S.A.M. was supported by a National Research Service Award in Molecular Biophysics (through NIH training grant PHS 5 T32 GM08276). We thank J. E. T. Corrie for gift of bis-rhodamine E. Gratton for initial suggestions and discussions B. C. Stevens for computer programming assistance and I. Rasnik for fluorescence imaging assistance.

Thông tin
Thông tin xuất bản

American Association for the Advancement of Science (AAAS)

Tập 300 Số 5628

2061-2065

Thông tin tác giả