A-site

{{refimprove|date=July 2014}}

The A-site (A for aminoacyl) of a ribosome is a binding site for charged t-RNA molecules during protein synthesis.{{cite journal|last1=Konevega|first1=AL|last2=Soboleva|first2=NG|last3=Makhno|first3=VI|last4=Semenkov|first4=YP|last5=Wintermeyer|first5=W|last6=Rodnina|first6=MV|last7=Katunin|first7=VI|title=Purine bases at position 37 of tRNA stabilize codon-anticodon interaction in the ribosomal A site by stacking and Mg2+-dependent interactions.|journal=RNA|date=Jan 2004|volume=10|issue=1|pages=90–101|pmid=14681588|pmc=1370521|doi=10.1261/rna.5142404}} One of three such binding sites, the A-site is the first location the t-RNA binds during the protein synthesis process, the other two sites being P-site (peptidyl) and E-site (exit).