---
title: Protein Viewer plugin
url: https://www.moldraw.com/docs/plugins/protein-viewer-plugin-view-pdb-structures-in-3d/
section: Plugins
updated: 2026-10-11
publisher: LabCanvas
---

# Protein Viewer plugin

> Open the Protein tab, type a PDB ID such as 1HHO and press Go. It is installed by default and works without signing in.

![MolDraw Protein Viewer showing haemoglobin 1HHO as green and blue cartoon chains with the amino-acid sequence strip below](https://www.moldraw.com/docs/img/plugin-proteins-annotated-screenshot.webp)
*Haemoglobin (PDB 1HHO) as a cartoon. Each chain has its own color. The sequence of chain A is below.*

1. Protein tab.
2. PDB ID box: type an ID and press Go (or use Open for a file).
3. Display menu: cartoon, sticks, lines, spheres and colouring.
4. Surface: molecular surface with opacity and colour.
5. Sequence strip: click residues to select and style them.

## What it does

Open the **Protein** tab next to Structure. Type a PDB ID like 1HHO, or load a file.

- **Display** sets the style: cartoon, stick or surface.
- Color by chain, secondary structure or element.
- Click the sequence strip to select residues.
- Export a PNG of the view.

## Who it is for

Biochemistry students. Teachers who need protein figures. Researchers who want a quick look at a structure.

## How to use it

1. Open the editor (no sign-in needed) and click the **Protein** tab (callout 1).
2. Type a PDB ID, e.g. `1HHO`, and press **Go** (callout 2), or press Open to load a local file.
3. Use **Display** (callout 3) to switch cartoon/sticks and colour by chain.
4. Add a **Surface** (callout 4) and lower its opacity to see the backbone.
5. Click residues in the **sequence strip** (callout 5) to highlight them.
6. Press **Export** to download an image.

## Tips

- Try 1HHO (haemoglobin), 1BNA (B-DNA), 6LU7 (SARS-CoV-2 main protease) or 1GFL (GFP).
- Calculate a protein's mass from its sequence with the [protein molecular weight calculator](https://www.moldraw.com/tools/free-chem-tools/protein-molecular-weight-calculator.html).
- For docking prep, use [PDB to PDBQT](https://www.moldraw.com/tools/free-chem-tools/pdb-to-pdbqt-converter.html).

## Questions and answers

**Do I need an account to view proteins?**
No. The Protein Viewer is installed by default and works without signing in.

**Which file formats can I open?**
PDB IDs are fetched directly; local PDB and mmCIF files can be opened from your computer.

**Can I show a ligand as sticks?**
Yes. Select the residue or ligand in the sequence strip and change its style.