# Error in input PDB file

**URL:** <https://ask.bioexcel.eu/t/error-in-input-pdb-file/4241>\
**Category:** Uncategorized\
**Created:** [April 3, 2023, 5:36am UTC](https://ask.bioexcel.eu/t/error-in-input-pdb-file/4241 "2023-04-03T05:36:29Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aanushkamehjabin](https://avatars.discourse-cdn.com/v4/letter/a/a88e4f/32.png) [@aanushkamehjabin](https://ask.bioexcel.eu/u/aanushkamehjabin)\
**Post date:** [April 3, 2023, 5:36am UTC](https://ask.bioexcel.eu/t/error-in-input-pdb-file/4241/1 "2023-04-03T05:36:29Z")

</div>

I am getting the following error for one of my input files,  
Error in PDB file.  
Issue when parsing the PDB file at line **729**.  
Your PDB contains an Unknown residue **PDBLine: ATOM 729 N HSD A 50 102.158 130.293 -28.820 1.00 0.00 AP1 N** that should be using HETATM record, please check the [HADDOCK library](https://wenmr.science.uu.nl/haddock2.4/library) for a list of supported modified residues.  
I am not sure how to resolve this