# Iron-Sulfur Cluster in Arsenite Oxidase
**URL:** https://ask.bioexcel.eu/t/iron-sulfur-cluster-in-arsenite-oxidase/1490
**Category:** HADDOCK
**Created:** [March 15, 2019, 3:58pm UTC](https://ask.bioexcel.eu/t/iron-sulfur-cluster-in-arsenite-oxidase/1490 "2019-03-15T15:58:47Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Filipa\_Engrola](https://ask.bioexcel.eu/u/Filipa_Engrola)
#### Post date: [March 15, 2019, 3:58pm UTC](https://ask.bioexcel.eu/t/iron-sulfur-cluster-in-arsenite-oxidase/1490/1 "2019-03-15T15:58:47Z")
Dear All,
I am interested to do the protein-protein docking of Arsenite oxidase with FES cluster and Cytochorome oxidase. We tried several times by changing the iron charges, iron numbering, etc. However we could not able to succeed at inputing the file. My protein four FE atoms and six sulfur atoms. Iam looking forward your kind response to fix this issue.
Please find the error related to this:
**"There was an inconsistency in your data**
**Error message**
**Second pdb file contains multiple forms of the same residue. This is not supported in the current form. If you would like to supply multiple conformations, please create an ensemble**
**ATOM 6647 1FE+2 F3S A2005 -3.573 -48.017 47.906 1.00 55.12 M Fe"**
Thanks in advance
Sincerely
Filipa
---
### Author:  [@amjjbonvin](https://ask.bioexcel.eu/u/amjjbonvin)
#### Post date: [March 17, 2019, 7:12pm UTC](https://ask.bioexcel.eu/t/iron-sulfur-cluster-in-arsenite-oxidase/1490/2 "2019-03-17T19:12:41Z")
Hi Filipa
The only supported iron cluster is with two FE and four Sulphur atoms:
```auto
CFE: CYS with an iron sulfur cluster.
HADDOCK will automatically search for closeby CYF residues and created bonds with the iron cluster
Atoms:
N,HN,CA,HA,CB,HB1,HB2,SG,FE1,SF1,FE2,SF2,C,O
```
The list of supported modified amino acids can be found at: [https://milou.science.uu.nl/services/HADDOCK2.2/library.html](https://milou.science.uu.nl/services/HADDOCK2.2/library.html)
You might try to define it as HETATM, but each atom must have a unique name.
Also from your PDB it seems you have multiple occupancies for the iron cluster