3B63

Actin filament model in the extended form of acromsomal bundle in the Limulus sperm


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 9.5 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: CRYSTALLOGRAPHY 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystallographic conformers of actin in a biologically active bundle of filaments.

Cong, Y.Topf, M.Sali, A.Matsudaira, P.Dougherty, M.Chiu, W.Schmid, M.F.

(2008) J.Mol.Biol. 375: 331-336

  • DOI: 10.1016/j.jmb.2007.10.027
  • Primary Citation of Related Structures:  3B5U

  • PubMed Abstract: 
  • Actin carries out many of its cellular functions through its filamentous form; thus, understanding the detailed structure of actin filaments is an essential step in achieving a mechanistic understanding of actin function. The acrosomal bundle in the ...

    Actin carries out many of its cellular functions through its filamentous form; thus, understanding the detailed structure of actin filaments is an essential step in achieving a mechanistic understanding of actin function. The acrosomal bundle in the Limulus sperm has been shown to be a quasi-crystalline array with an asymmetric unit composed of a filament with 14 actin-scruin pairs. The bundle in its true discharge state penetrates the jelly coat of the egg. Our previous electron crystallographic reconstruction demonstrated that the actin filament cross-linked by scruin in this acrosomal bundle state deviates significantly from a perfect F-actin helix. In that study, the tertiary structure of each of the 14 actin protomers in the asymmetric unit of the bundle filament was assumed to be constant. In the current study, an actin filament atomic model in the acrosomal bundle has been refined by combining rigid-body docking with multiple actin crystal structures from the Protein Data Bank and constrained energy minimization. Our observation demonstrates that actin protomers adopt different tertiary conformations when they form an actin filament in the bundle. The scruin and bundle packing forces appear to influence the tertiary and quaternary conformations of actin in the filament of this biologically active bundle.


    Organizational Affiliation

    National Center for Macromolecular Imaging and Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA. mschmid@bcm.tmc.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Actin
A, G
365Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Actin
B
364Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Actin
C, I
365Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
Actin
D
357Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Entity ID: 5
MoleculeChainsSequence LengthOrganismDetails
Actin
E, H, J, K, N
365Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Entity ID: 6
MoleculeChainsSequence LengthOrganismDetails
Actin
F
357Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Entity ID: 7
MoleculeChainsSequence LengthOrganismDetails
Actin
L, M
365Limulus polyphemusN/A
Find proteins for P41340 (Limulus polyphemus)
Go to UniProtKB:  P41340
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 9.5 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: CRYSTALLOGRAPHY 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-11-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2012-05-30
    Type: Refinement description