<p>In general, an <em>accession</em> is a value that points to (provides <em>access</em> to) a single database entry. Different databases (GenBank, RefSeq, Ensembl, SwissProt, and so on) have different conventions for accessions.</p>
<p>The accession in question points to an RNA sequence associated with a <a href="https://www.rcsb.org/sequence/6MWN" rel="nofollow noreferrer">Protein Data Bank (PDB) record</a>: &quot;Crystal structure of hepatitis A virus IRES domain V in complex with Fab HAVx&quot;. In the PDB record, you can click the &quot;sequence&quot; tab and select chain &quot;B&quot; from the drop-down, and you will see an RNA sequence (ACGU) matching the DNA sequence (ACGT) in the NCBI record to which you linked.</p>
<p>I'm not sure what the rules or conventions for PDB accessions are, but they are clearly different from RefSeq accessions.</p>

CC BY-SA 4.0
2022-05-06T13:56:16.043Z
Thank you! I am just surprised that this lies in *nuccore* & did not get a new local accession code.
Vovin
CC BY-SA 4.0
2022-05-06T13:23:39.557Z
2022-05-06T13:23:39.557Z
Daniel Standage
<p>According to <a href="https://www.ncbi.nlm.nih.gov/genbank/samplerecord/" rel="nofollow noreferrer">this article</a>, accession codes should consist from a combination of uppercase letters following a combination of digits. If this is a <em>RefSeq</em>, it can have a prefix as a combination of uppercase letters with underscore.</p>
<p>But this accession code <a href="https://www.ncbi.nlm.nih.gov/nuccore/6MWN_B" rel="nofollow noreferrer"><strong>6MWN_B</strong></a> does not consist with all aforementioned. What is it? I could not find an answer via Google.</p>

<phylogenetics><genbank>
What does this accession NCBI code mean: 6MWN_B?
# What does this accession NCBI code mean: 6MWN_B?

(Asked by: username_0 on 2022-05-06)

According to [this article](https://www.ncbi.nlm.nih.gov/genbank/samplerecord/), accession codes should consist from a combination of uppercase letters following a combination of digits. If this is a *RefSeq*, it can have a prefix as a combination of uppercase letters with underscore.

But this accession code [**6MWN\_B**](https://www.ncbi.nlm.nih.gov/nuccore/6MWN_B) does not consist with all aforementioned. What is it? I could not find an answer via Google.

**Tags:** phylogenetics, genbank

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## 1 answers

### Answer by username_1 on 2022-05-06. Score: 3 | Accepted answer

In general, an *accession* is a value that points to (provides *access* to) a single database entry. Different databases (GenBank, RefSeq, Ensembl, SwissProt, and so on) have different conventions for accessions.

The accession in question points to an RNA sequence associated with a [Protein Data Bank (PDB) record](https://www.rcsb.org/sequence/6MWN): "Crystal structure of hepatitis A virus IRES domain V in complex with Fab HAVx". In the PDB record, you can click the "sequence" tab and select chain "B" from the drop-down, and you will see an RNA sequence (ACGU) matching the DNA sequence (ACGT) in the NCBI record to which you linked.

I'm not sure what the rules or conventions for PDB accessions are, but they are clearly different from RefSeq accessions.

> **Comments:**
> **username_0**: Thank you! I am just surprised that this lies in *nuccore* & did not get a new local accession code.  

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