P49321: Nuclear autoantigenic sperm protein (NASP)

Nuclear autoantigenic sperm protein (NASP) is a 788-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P49321.

Gene
NASP
Organism
Homo sapiens
Length
788 residues
Mean pLDDT
57.3
Model
AF-P49321-F1 v6
Model created
1 Aug 2025
PDB structures
5

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Model confidence (pLDDT)

The mean pLDDT of this model is 57.3 (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 accurate26%
70 to 90Confident: backbone generally right6%
50 to 70Low: treat with caution8%
Below 50Very low: often disordered regions61%

What pLDDT means and how to read it

Function

Component of the histone chaperone network (PubMed:22195965). Binds and stabilizes histone H3-H4 not bound to chromatin to maintain a soluble reservoir and modulate degradation by chaperone-mediated autophagy (PubMed:22195965). Required for DNA replication, normal cell cycle progression and cell proliferation. Forms a cytoplasmic complex with HSP90 and H1 linker histones and stimulates HSP90 ATPase activity. NASP and H1 histone are subsequently released from the complex and translocate to the nucleus where the histone is released for binding to DNA

Subunit structure

Binds to linker H1 histones (By similarity). Interacts with histones H2A, H2B, H3 and H4 (PubMed:27618665, PubMed:8724350). Interacts with histone H3.3 (PubMed:33857403). Interacts with histones H3 and H4; NASP is a histone chaperone that stabilizes and maintains a soluble pool of histone H3-H4 dimers (PubMed:22195965). Interacts with ASF1A and ASF1B; the interaction is probably indirect and…

Subcellular location

Cytoplasm, Nucleus

Experimental structures in the PDB

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

PDB IDMethodResolutionChains and residues
7V1MX-ray2.83 ÅG/H=499-662
7V1LX-ray2.85 ÅB=499-679
7V6PX-ray2.9 ÅA=454-659
7V6QX-ray3.0 ÅD/H=454-659
7V1KX-ray3.29 ÅA=499-679

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