Database accession: MF4130001
Name: Tetrabrachion tetramerization region
PDB ID: 1fe6
Experimental method: X-ray (1.80 Å)
Assembly: homotetramer
Source organism: Staphylothermus marinus
Primer publication of the structure:
Stetefeld J, Jenny M, Schulthess T, Landwehr R, Engel J, Kammerer RA
Crystal structure of a naturally occurring parallel right-handed coiled coil tetramer.
(2000) Nat. Struct. Biol. 7: 772-6
PMID: 10966648
Abstract:
The crystal structure of a polypeptide chain fragment from the surface layer protein tetrabrachion from Staphylothermus marinus has been determined at 1.8 A resolution. As proposed on the basis of the presence of 11-residue repeats, the polypeptide chain fragment forms a parallel right-handed coiled coil structure. Complementary hydrophobic interactions and complex networks of surface salt bridges result in an extremely thermostable tetrameric structure with remarkable properties. In marked contrast to left-handed coiled coil tetramers, the right-handed coiled coil reveals large hydrophobic cavities that are filled with water molecules. As a consequence, the packing of the hydrophobic core differs markedly from that of a right-handed parallel coiled coil tetramer that was designed on the basis of left-handed coiled coil structures.
Molecular function: not assigned
Biological process: not assigned
Cellular component:
integral component of membrane The component of a membrane consisting of the gene products and protein complexes having at least some part of their peptide sequence embedded in the hydrophobic region of the membrane.
Entry contents: 4 distinct polypeptide molecules
Chains: A, B, C, D
Notes: No modifications of the original PDB file. Chain identifiers are identical with the PDB's identifiers.
Number of unique protein segments: 1
Name: Tetrabrachion (Precursor)
Source organism: Staphylothermus marinus
Length: 52 residues
Sequence:Sequence according to PDB SEQRESGSIINETADDIVYRLTVIIDDRYESLKNLITLRADRLEMIINDNVSTILASG
UniProtKB AC: Q54436 (positions: 1236-1287)
Coverage: 3.4%UniRef90 AC: UniRef90_Q54436 (positions: 1237-1286)
Name: Tetrabrachion (Precursor)
Source organism: Staphylothermus marinus
Length: 52 residues
Sequence:Sequence according to PDB SEQRESGSIINETADDIVYRLTVIIDDRYESLKNLITLRADRLEMIINDNVSTILASG
UniProtKB AC: Q54436 (positions: 1236-1287)
Coverage: 3.4%UniRef90 AC: UniRef90_Q54436 (positions: 1237-1286)
Name: Tetrabrachion (Precursor)
Source organism: Staphylothermus marinus
Length: 52 residues
Sequence:Sequence according to PDB SEQRESGSIINETADDIVYRLTVIIDDRYESLKNLITLRADRLEMIINDNVSTILASG
UniProtKB AC: Q54436 (positions: 1236-1287)
Coverage: 3.4%UniRef90 AC: UniRef90_Q54436 (positions: 1237-1286)
Name: Tetrabrachion (Precursor)
Source organism: Staphylothermus marinus
Length: 52 residues
Sequence:Sequence according to PDB SEQRESGSIINETADDIVYRLTVIIDDRYESLKNLITLRADRLEMIINDNVSTILASG
UniProtKB AC: Q54436 (positions: 1236-1287)
Coverage: 3.4%UniRef90 AC: UniRef90_Q54436 (positions: 1237-1286)
Complex evidence:
The subunits in the structure are bound via coiled coil interactions (PMID: 10966648). Coiled coils are highly versatile folding units (PMID: 11166216), where the formation of the structure and the interaction between subunits is almost ubiquitously linked. This cooperative nature of binding and folding that results in a two-step process has been demonstrated for coiled coils with varying oligomeric state from dimers (PMID: 9811815) and trimers (PMID: 10933510) up to heptamers (PMID: 17030805). While the interaction and folding are linked, in certain cases there can be significant residual structure before association (PMID: 8401212). However, these residual structural elements usually encompass 1-2 turns of helices that serve as a 'nucleation site' driving interaction and helix formation (zipping up) (PMID: 17438295), thus even in these cases monomeric coiled coil subunits cannot be considered to have a stable structure.