PDBsum entry 4l79

Motor protein/metal binding protein

PDB id: 4l79

Contents

Protein chains

734 a.a.

147 a.a.

Metals

_MG

Waters ×459

PDB id:

4l79

Name:

Motor protein/metal binding protein

Title:

Crystal structure of nucleotide-free myosin 1b residues 1-728 with bound calmodulin

Structure:

Unconventional myosin-ib. Chain: a. Fragment: unp residues 1-728. Synonym: myosin i alpha, mmi-alpha, mmia, myosin heavy chain myr 1. Engineered: yes. Calmodulin. Chain: b. Synonym: cam. Engineered: yes

Source:

Rattus norvegicus. Brown rat,rat,rats. Organism_taxid: 10116. Gene: myo1a, myo1b, myr1. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108. Homo sapiens. Human. Organism_taxid: 9606.

Resolution:

2.30Å R-factor: 0.192 R-free: 0.249

Authors:

H.Shuman,A.Zwolak,R.Dominguez,E.M.Ostap

Key ref:

H.Shuman et al. (2014). A vertebrate myosin-I structure reveals unique insights into myosin mechanochemical tuning. Proc Natl Acad Sci U S A, 111, 2116-2121. PubMed id: 24469830 DOI: 10.1073/pnas.1321022111

Date:

13-Jun-13 Release date: 29-Jan-14

Protein chain

Q05096  (MYO1B_RAT) -  Unconventional myosin-Ib from Rattus norvegicus

Seq: 1136 a.a.

Struc: 734 a.a.*

Protein chain

P0DP23  (CALM1_HUMAN) -  Calmodulin-1 from Homo sapiens

Seq: 149 a.a.

Struc: 147 a.a.

* PDB and UniProt seqs differ at 15 residue positions (black crosses)

DOI no: 10.1073/pnas.1321022111

Proc Natl Acad Sci U S A 111:2116-2121 (2014)

PubMed id: 24469830

A vertebrate myosin-I structure reveals unique insights into myosin mechanochemical tuning.

H.Shuman, M.J.Greenberg, A.Zwolak, T.Lin, C.V.Sindelar, R.Dominguez, E.M.Ostap.

ABSTRACT

Myosins are molecular motors that power diverse cellular processes, such as rapid organelle transport, muscle contraction, and tension-sensitive anchoring. The structural adaptations in the motor that allow for this functional diversity are not known, due, in part, to the lack of high-resolution structures of highly tension-sensitive myosins. We determined a 2.3-Å resolution structure of apo-myosin-Ib (Myo1b), which is the most tension-sensitive myosin characterized. We identified a striking unique orientation of structural elements that position the motor's lever arm. This orientation results in a cavity between the motor and lever arm that holds a 10-residue stretch of N-terminal amino acids, a region that is divergent among myosins. Single-molecule and biochemical analyses show that the N terminus plays an important role in stabilizing the post power-stroke conformation of Myo1b and in tuning the rate of the force-sensitive transition. We propose that this region plays a general role in tuning the mechanochemical properties of myosins.