Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 16: Molecular Motors
BP 16.4: Vortrag
Mittwoch, 28. März 2012, 16:15–16:30, H 1028
Altering the Native Neck-Linker Length Changes Processivity of Kinesin-5 Motor Proteins — •André Düselder1, Christina Thiede1, Stefanie Kramer1, Stefan Lakämper2, and Christoph F. Schmidt1 — 1Drittes Physikalisches Institut, Georg-August-Universität Göttingen, Germany — 2current address: Institute for Mechanical Systems, D-MAVT, ETH Zurich, Switzerland
Processivity for kinesins relies on communication between the two heads of a dimeric molecule, such that binding strictly alternates. The main communicating elements are believed to be the neck linkers (NL). One proposed mechanism for the coordination is the transmission of intra-molecular stress through the NL, a mechanism dubbed front- or rear-head gating. It is believed that the efficiency of gating should dependent on the length of the NL. Recent studies have presented support for a simple model in which the length of the NL directly controls the degree of processivity. Here, we have analyzed the motility of a set of six motor constructs, based on a previously published Kinesin-1/Kinesin-5 chimera, Eg5Kin, in which we have now varied the length of the NL, starting from 13 amino acids up to the native 18 amino acids of Eg5. We found, surprisingly, that neither velocity nor force generation depended on the NL length. We also found that even the construct with the shortest NL was highly processive, and that the longest NL (17 and 18 amino acids) allowed run lengths twice those of the other constructs. This finding challenges the simple model equating a short NL with tight communication, but suggests that different kinesins might be optimized for different NL lengths.