PDBsum entry 3l1c

Motor protein

PDB id: 3l1c

Contents

Protein chains

355 a.a. *

331 a.a. *

Ligands

ADP ×2

Metals

_MG ×2

Waters ×243

* Residue conservation analysis

PDB id:

3l1c

Name:

Motor protein

Title:

Kinesin-14 protein ncd, t436s mutant

Structure:

Protein claret segregational. Chain: a, b. Fragment: residues 293-674. Engineered: yes. Mutation: yes

Source:

Drosophila melanogaster. Fruit fly. Organism_taxid: 7227. Gene: ncd. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.75Å R-factor: 0.238 R-free: 0.292

Authors:

F.J.Kull

Key ref:

E.Heuston et al. (2010). A kinesin motor in a force-producing conformation. Bmc Struct Biol, 10, 19. PubMed id: 20602775

Date:

11-Dec-09 Release date: 18-Aug-10

Protein chain

P20480  (NCD_DROME) -  Protein claret segregational from Drosophila melanogaster

Seq: 700 a.a.

Struc: 355 a.a.*

Protein chain

P20480  (NCD_DROME) -  Protein claret segregational from Drosophila melanogaster

Seq: 700 a.a.

Struc: 331 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

Enzyme reactions

• Enzyme class: Chains A, B: E.C.3.6.4.- - ?????

Bmc Struct Biol 10:19 (2010)

PubMed id: 20602775

A kinesin motor in a force-producing conformation.

E.Heuston, C.E.Bronner, F.J.Kull, S.A.Endow.

ABSTRACT

ABSTRACT: BACKGROUND: Kinesin motors hydrolyze ATP to produce force and move along microtubules, converting chemical energy into work by a mechanism that is only poorly understood. Key transitions and intermediate states in the process are still structurally uncharacterized, and remain outstanding questions in the field. Perturbing the motor by introducing point mutations could stabilize transitional or unstable states, providing critical information about these rarer states. RESULTS: Here we show that mutation of a single residue in the kinesin-14 Ncd causes the motor to release ADP and hydrolyze ATP faster than wild type, but move more slowly along microtubules in gliding assays, uncoupling nucleotide hydrolysis from force generation. A crystal structure of the motor shows a large rotation of the stalk, a conformation representing a force-producing stroke of Ncd. Three C-terminal residues of Ncd, visible for the first time, interact with the central beta-sheet and dock onto the motor core, forming a structure resembling the kinesin-1 neck linker, which has been proposed to be the primary force-generating mechanical element of kinesin-1. CONCLUSIONS: Force generation by minus-end Ncd involves docking of the C-terminus, which forms a structure resembling the kinesin-1 neck linker. The mechanism by which the plus- and minus-end motors produce force to move to opposite ends of the microtubule appears to involve the same conformational changes, but distinct structural linkers. Unstable ADP binding may destabilize the motor-ADP state, triggering Ncd stalk rotation and C-terminus docking, producing a working stroke of the motor.