PDBsum entry 1lvk

Contractile protein

PDB id: 1lvk

Contents

Protein chain

743 a.a. *

Ligands

MNT-BEF

Metals

_MG

Waters ×2

* Residue conservation analysis

PDB id:

1lvk

Name:

Contractile protein

Title:

X-ray crystal structure of the mg (dot) 2'(3')-o-(n- methylanthraniloyl) nucleotide bound to dictyostelium discoideum myosin motor domain

Structure:

Myosin. Chain: a. Fragment: motor domain. Engineered: yes. Mutation: yes. Other_details: genetically truncated head of myosin from dictyostelium

Source:

Dictyostelium discoideum. Organism_taxid: 44689. Expressed in: dictyostelium discoideum. Expression_system_taxid: 44689

Resolution:

1.90Å R-factor: 0.200

Authors:

C.B.Bauer,P.A.Kuhlman,C.R.Bagshaw,I.Rayment

Key ref:

C.B.Bauer et al. (1997). X-ray crystal structure and solution fluorescence characterization of Mg.2'(3')-O-(N-methylanthraniloyl) nucleotides bound to the Dictyostelium discoideum myosin motor domain. J Mol Biol, 274, 394-407. PubMed id: 9405148 DOI: 10.1006/jmbi.1997.1325

Date:

05-Sep-97 Release date: 28-Jan-98

Protein chain

P08799  (MYS2_DICDI) -  Myosin-2 heavy chain from Dictyostelium discoideum

Seq: 2116 a.a.

Struc: 743 a.a.*

* PDB and UniProt seqs differ at 12 residue positions (black crosses)

DOI no: 10.1006/jmbi.1997.1325

J Mol Biol 274:394-407 (1997)

PubMed id: 9405148

X-ray crystal structure and solution fluorescence characterization of Mg.2'(3')-O-(N-methylanthraniloyl) nucleotides bound to the Dictyostelium discoideum myosin motor domain.

C.B.Bauer, P.A.Kuhlman, C.R.Bagshaw, I.Rayment.

ABSTRACT

Mant (2'(3')-O-(N-methylanthraniloyl)) labeled nucleotides have proven to be useful tools in the study of the kinetic mechanism of the myosin ATPase by fluorescence spectroscopy. The sensitivity of the mant fluorophore to its local environment also makes it suitable to investigate the exposure of bound nucleotides to solvent from collisional quenching measurements. Here we present the crystal structure of mant-ADP and beryllium fluoride complexed with Dictyostelium discoideum myosin motor domain (S1dC) at 1.9 A resolution. We complement the structural approach with an investigation of the accessibility of the mant moiety to solvent using acrylamide quenching of fluorescence emission. In contrast to rabbit skeletal myosin subfragment 1, where the mant group is protected from acrylamide (Ksv=0.2 M-1), the fluorophore is relatively exposed when bound to Dictyostelium myosin motor domain (Ksv= 1.4 M-1). Differences between the Dictyostelium structure and that of vertebrate skeletal subfragment 1, in the region of the nucleotide binding pocket, are proposed as an explanation for the differences observed in the solvent accessibility of complexed mant-nucleotides. We conclude that protection of the mant group from acrylamide quenching does not report on overall closure of the nucleotide binding pocket but reflects more local structural changes.

Selected figure(s)

Figure 6.
Figure 6. Stereo ribbon representation of the portion of S1dC heavy chain which is in close contact with the mant ring. The side-chains which make contacts with the mant ring of less than 5.0 Å are shown with yellow bonds for the S1dC complex. The corresponding side-chains for chicken S1 are shown with thin black bonds. Residues labeled with their three letter code refer to the sequence and structure of Dictyostelium myosin whereas those labeled with the single letter code for the amino acid residues refer to chicken skeletal myosin. This figure was prepared with the molecular graphics program MOLSCRIPT [Kraulis 1991].

Figure 7.
Figure 7. Stereo view of representative electron density associated with the central 50 kDa section of the polypeptide chain located near the fluorescent mant ring and calculated with coefficients of the form 2F[o]−F[c]. This Figure was prepared with the graphics programs MOLDED [Fisher 1996] and MOLSCRIPT [Kraulis 1991].

The above figures are reprinted by permission from Elsevier: J Mol Biol (1997, 274, 394-407) copyright 1997.

Figures were selected by an automated process.