Cryo-EM structure of the MamK filament at 6.5 A

Experimental Data Snapshot

  • Resolution: 6.50 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

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Structure of the magnetosome-associated actin-like MamK filament at subnanometer resolution.

Bergeron, J.R.Hutto, R.Ozyamak, E.Hom, N.Hansen, J.Draper, O.Byrne, M.E.Keyhani, S.Komeili, A.Kollman, J.M.

(2017) Protein Sci 26: 93-102

  • DOI: https://doi.org/10.1002/pro.2979
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Magnetotactic bacteria possess cellular compartments called magnetosomes that sense magnetic fields. Alignment of magnetosomes in the bacterial cell is necessary for their function, and this is achieved through anchoring of magnetosomes to filaments composed of the protein MamK. MamK is an actin homolog that polymerizes upon ATP binding. Here, we report the structure of the MamK filament at ∼6.5 Å, obtained by cryo-Electron Microscopy. This structure confirms our previously reported double-stranded, nonstaggered architecture, and reveals the molecular basis for filament formation. While MamK is closest in sequence to the bacterial actin MreB, the longitudinal contacts along each MamK strand most closely resemble those of eukaryotic actin. In contrast, the cross-strand interface, with a surprisingly limited set of contacts, is novel among actin homologs and gives rise to the nonstaggered architecture.

  • Organizational Affiliation

    Department of Plant and Microbial Biology, University of California, Berkeley, California.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Actin-like ATPase
A, B, C, D, E
A, B, C, D, E, F, G, H, I, J, K, L, M, N
347Paramagnetospirillum magneticum AMB-1Mutation(s): 0 
Gene Names: amb0965
Find proteins for Q2W8Q6 (Magnetospirillum magneticum (strain AMB-1 / ATCC 700264))
Explore Q2W8Q6 
Go to UniProtKB:  Q2W8Q6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2W8Q6
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on ADP

Download Ideal Coordinates CCD File 
BA [auth G]
DA [auth H]
FA [auth I]
HA [auth J]
JA [auth K]
BA [auth G],
DA [auth H],
FA [auth I],
HA [auth J],
JA [auth K],
LA [auth L],
NA [auth M],
P [auth A],
PA [auth N],
R [auth B],
T [auth C],
V [auth D],
X [auth E],
Z [auth F]
C10 H15 N5 O10 P2
Query on MG

Download Ideal Coordinates CCD File 
AA [auth G]
CA [auth H]
EA [auth I]
GA [auth J]
IA [auth K]
AA [auth G],
CA [auth H],
EA [auth I],
GA [auth J],
IA [auth K],
KA [auth L],
MA [auth M],
O [auth A],
OA [auth N],
Q [auth B],
S [auth C],
U [auth D],
W [auth E],
Y [auth F]
Experimental Data & Validation

Experimental Data

  • Resolution: 6.50 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 
EM Software:
TaskSoftware PackageVersion

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-07-27
    Type: Initial release
  • Version 1.1: 2017-01-11
    Changes: Database references