locus tag to NCBI Accession number (SIMPLE gene ID conversion question)

You can use EntrezDirect:

$ esearch -db nucleotide -query "OG1RF_10009" | efetch -format acc
NC_017316.1
CP002621.1

NC* is RefSeq entry while the other is normal genome.

If you have multiple locus tags then you should be able to use epost method to seach them all.

---

If you need to be a little more specific than the genome accession then you can do the following.

$ esearch -db gene -query "OG1RF_10009" | efetch -format ft

1. rpsR
30S ribosomal protein S18 [Enterococcus faecalis OG1RF]
Other Aliases: OG1RF_10009
Annotation:  NC_017316.1 (10289..10528)
This record was discontinued.
ID: 12287861

---

$ esearch -db protein -query "OG1RF_10009" | efetch -format acc
AEA92696.1

$ esearch -db protein -query "OG1RF_10009" | efetch -format ft
>Feature gb|AEA92696.1|
1   79  Protein
            product 30S ribosomal protein S18
14  77  Region
            region  rpsR
            note    30S ribosomal protein S18; Reviewed
            db_xref CDD:178997
1   79  CDS
            product 30S ribosomal protein S18
            transl_table    11
            protein_id  gb|AEA92696.1||gnl|bcmhgsc|OG1RF_10009
            note    COG: COG0238; Pfam: PF01084; InterPro: IPR001648