General Information

Database accession: MF2110007

Name: Delta sleep-inducing peptide immunoreactive peptide A homolog

PDB ID: 1dip PDB

Experimental method: NMR

Assembly: homodimer

Source organism: Sus scrofa

Primer publication of the structure:

Seidel G, Adermann K, Schindler T, Ejchart A, Jaenicke R, Forssmann WG, Rösch P
Solution structure of porcine delta sleep-inducing peptide immunoreactive peptide A homolog of the shortsighted gene product.

(1997) J. Biol. Chem. 272: 30918-27

PMID: 9388238 PubMed


The 77-residue delta sleep-inducing peptide immunoreactive peptide (DIP) is a close homolog of the Drosophila melanogaster shortsighted gene product. Porcine DIP (pDIP) and a peptide containing a leucine zipper-related partial sequence of pDIP, pDIP(9-46), was synthesized and studied by circular dichroism and nuclear magnetic resonance spectroscopy in combination with molecular dynamics calculations. Ultracentrifugation, size exclusion chromatography, and model calculations indicated that pDIP forms a dimer. This was confirmed by the observation of concentration-dependent thermal folding-unfolding transitions. From CD spectroscopy and thermal folding-unfolding transitions of pDIP(9-46), it was concluded that the dimerization of pDIP is a result of interaction between helical structures localized in the leucine zipper motif. The three-dimensional structure of the protein was determined with a modified simulated annealing protocol using experimental data derived from nuclear magnetic resonance spectra and a modeling approach based on an established strategy for coiled coil structures. The left-handed super helical structure of the leucine zipper type sequence resulting from the modeling approach is in agreement with known leucine zipper structures. In addition to the hydrophobic interactions between the amino acids at the heptade positions a and d, the structure of pDIP is stabilized by the formation of interhelical i to i' + 5 salt bridges. This result was confirmed by the pH dependence of the thermal-folding transitions. In addition to the amphipatic helix of the leucine zipper, a second helix is formed in the NH2-terminal part of pDIP. This helix exhibits more 310-helix character and is less stable than the leucine zipper helix. For the COOH-terminal region of pDIP no elements of regular secondary structure were observed.

Function and Biology Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown.

Molecular function:

transcription factor activity, sequence-specific DNA binding Interacting selectively and non-covalently with a specific DNA sequence in order to modulate transcription. The transcription factor may or may not also interact selectively with a protein or macromolecular complex. GeneOntology

Biological process:

negative regulation of activation-induced cell death of T cells Any process that stops, prevents, or reduces the frequency, rate or extent of activation-induced cell death of T cells. GeneOntology

regulation of transcription, DNA-templated Any process that modulates the frequency, rate or extent of cellular DNA-templated transcription. GeneOntology

Cellular component:

nucleus A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent. GeneOntology

cytoplasm All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. GeneOntology

Structure Summary Structural annotations of the participating protein chains.

Entry contents: 2 distinct polypeptide molecules

Chains: A, B

Notes: No modifications of the original PDB file. Chain identifiers are identical with the PDB's identifiers.

Number of unique protein segments: 1

Chain A

Name: TSC22 domain family protein 3

Source organism: Sus scrofa

Length: 77 residues


UniProtKB AC: P80220 (positions: 1-77) UniProt Coverage: 100%

UniRef90 AC: UniRef90_P80220 (positions: 1-77) UniRef90

Chain B

Name: TSC22 domain family protein 3

Source organism: Sus scrofa

Length: 77 residues


UniProtKB AC: P80220 (positions: 1-77) UniProt Coverage: 100%

UniRef90 AC: UniRef90_P80220 (positions: 1-77) UniRef90

Evidence Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding.

Complex evidence:

The subunits in the structure are bound via coiled coil interactions (PMID: 9388238). 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. Leucine zippers, phenylalanine zippers and alanine zippers are subclasses of coiled coils where the hydrophobic interactions between subunits are predominantly formed by leucine, phenylalanine or alanine residues, respectively.

Related Structure(s) Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap).

No related structure was found in the Protein Data Bank.

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