4nnk is a 1 chain structure with sequence from Mycobacterium tuberculosis H37Rv. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
RS1_MYCTU Binds mRNA; thus facilitating recognition of the initiation point. It is needed to translate mRNA with a short Shine-Dalgarno (SD) purine-rich sequence (By similarity).