One of the primary rRNA binding proteins, it binds specifically to the 5'-end of 16S ribosomal RNA (By similarity). Required for optimal plastid performance in terms of photosynthesis and growth. Required for the translation of plastid mRNAs. Plays a critical role in biosynthesis of thylakoid membrane proteins encoded by chloroplast genes (PubMed:22900828). Part of the 30S ribosomal subunit. Reduced plant size and pale green leaves. Belongs to the universal ribosomal protein uS17 family. Extended N-terminus.