I have a few new Locus tags as follows:

    RS09560
    RS10020
    RS10595

and I need to convert them into old Locus tag which are 

    RS09560	    NA
    RS10020	    1984
    RS10595	    2097


NA are the ones with not available old locus tag. I couldn't find any database to do so. And the information available for old locus tag and new locus tag is in the NCBI website

https://www.ncbi.nlm.nih.gov/nuccore/NC_000962.3

I tried to scarp the data from the website using R (rvest) and had written a few lines, but skeptical about the **HTML node** I should extract from the web page **to get the information about old locus tag and new locus tag**.

    > library(xml2)
    > library(rvest)
    > url <- 'https://www.ncbi.nlm.nih.gov/nuccore/NC_000962.3'
    > webpage <- read_html(url)
    > sb_table <- html_nodes(webpage, ' ')

Please suggest a way to do and also which node could be used to fetch the locus tags.


I'm a python type of guy, and what I would do is to set up a script to [parse through the genbank file using biopython.][1]

I wouldn't expect to find any source that has any old locus names that are missing from the NCBI genbank files. Gene annotations are constantly updated and it's not unusual for 'novel' genes to pop up, which will not have an old locus name.

Assuming that what you have is a neat list of accessions of interest, it is just a matter of looping through the 'Features' and looking for the accessions, grabbing the old locus names if available, and print a simple list of new vs old accessions.

Even if you have not touched python yet, it is a fairly easy and decent introduction to it if you are willing to give it a go.


  [1]: http://biopython.org/DIST/docs/tutorial/Tutorial.html