# DNAJC24 (Q6P3W2) research notes

Small cytoplasmic J-domain co-chaperone of the HSP70 system that also functions in
**diphthamide biosynthesis**. Also named DPH4 / ZCSL3.

## Architecture
- N-terminal **J-domain** (canonical HPD motif) that stimulates HSP70 ATPase activity.
- C-terminal **DPH-type CSL** metal-binding domain coordinating Zn or Fe; iron binding
  promotes oligomerization and confers redox/electron-carrier activity. [PMID:22367199;
  PMID:22509046]

## Function
- Component of the conserved multi-step diphthamide pathway that installs the
  diphthamide modification on a specific histidine of translation elongation factor 2
  (**EEF2**) — the residue targeted by diphtheria toxin and Pseudomonas exotoxin A.
  [UniProt Q6P3W2; PMID:22367199]

## Curation calls
- Core MFs: ATPase activator activity (GO:0001671, stimulates HSP70); protein histidyl
  modification to diphthamide (GO:0017183).
- An actin-cytoskeleton annotation (orthology transfer) marked over-annotated.