BiomaRt error: Error in martCheck
getSequence has only been enabled for the main Ensembl (vertebrates) biomaRt. This is all at the Bioconductor end. You'll need to use a getBM instead, for example:

os_genes &lt;- getBM(attributes =c("ensembl_transcript_id", "peptide"), filters = "ensembl_transcript_id", values = osj_id, mart = osj)