P48607: Protein spaetzle (spz)

Protein spaetzle (spz) is a 326-residue protein from Drosophila melanogaster. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P48607.

Gene
spz
Organism
Drosophila melanogaster
Length
326 residues
Mean pLDDT
66.0
Model
AF-P48607-F1 v6
Model created
1 Aug 2025
PDB structures
4

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Model confidence (pLDDT)

The mean pLDDT of this model is 66.0 (low overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.

pLDDT bandMeaningShare of residues
Above 90Very high: backbone and side chains are usually accurate28%
70 to 90Confident: backbone generally right20%
50 to 70Low: treat with caution16%
Below 50Very low: often disordered regions36%

What pLDDT means and how to read it

Function

The activated form, spaetzle C-106, acts as a ligand for the Toll receptor (PubMed:12872120). Binding to Toll activates the Toll signaling pathway and induces expression of the antifungal peptide drosomycin (PubMed:8808632). Component of the extracellular signaling pathway that establishes dorsal-ventral polarity in the embryo (PubMed:11212919, PubMed:8124709)

Subunit structure

Homodimer; disulfide-linked (PubMed:12872120, PubMed:9533958). In the presence of Tl, crystal structures show one Tl molecule bound to a spaetzle C-106 homodimer (PubMed:24282309, PubMed:24733933). However, the active complex probably consists of two Tl molecules bound to a spaetzle C-106 homodimer (PubMed:24282309, PubMed:24733933). This is supported by in vitro experiments which also show…

Subcellular location

Secreted

Experimental structures in the PDB

Compare the prediction with experimentally determined structures of the same protein:

PDB IDMethodResolutionChains and residues
4LXRX-ray2.2 ÅJ/K=221-326
4BV4X-ray2.35 ÅL/M=221-326
3E07X-ray2.4 ÅA/B=221-326
4LXSX-ray3.3 ÅJ/K=221-326

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