Query BioMart with httr and RCurl

BioMart_query.R

fullXmlQuery <- "<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE Query>
        <Query  virtualSchemaName = 'default' uniqueRows = '1' count = '0' datasetConfigVersion = '0.6' header='1' requestid= 'biomaRt'>
            <Dataset name = 'hsapiens_gene_ensembl'>
                <Attribute name = 'ensembl_transcript_id'/>
                <Attribute name = 'ensembl_exon_id'/>
                <Attribute name = 'rank'/>
                <Attribute name = 'genomic_coding_start'/>
                <Attribute name = 'cds_start'/>
                <Attribute name = '5_utr_start'/>
            </Dataset>
        </Query>"

rcurl_return <- RCurl::postForm(uri = "http://www.ensembl.org:80/biomart/martservice?", 
                                "query" = fullXmlQuery)
httr_return <- httr::content(httr::POST(url = "http://www.ensembl.org:80/biomart/martservice?",
                                        body = list(query = fullXmlQuery)))

grep('ENST00000485971', rcurl_return)
grep('ENST00000485971', httr_return)