This entry represents an extension found at the N-terminal of mammalian 28S ribosomal protein S5 [1,2]. This lines a part of the mRNA entry path and connects the 28S subunit body to the head forming a latch across the mRNA channel entrance [2].

1: Cryo-EM structure of the small subunit of the mammalian mitochondrial ribosome. Kaushal PS, Sharma MR, Booth TM, Haque EM, Tung CS, Sanbonmatsu KY, Spremulli LL, Agrawal RK; Proc Natl Acad Sci U S A. 2014;111:7284-7289. PMID:24799711

2: Ribosome. The complete structure of the 55S mammalian mitochondrial ribosome. Greber BJ, Bieri P, Leibundgut M, Leitner A, Aebersold R, Boehringer D, Ban N; Science. 2015;348:303-308. PMID:25837512