What features distinguish expression vectors from cloning vectors?

Expression vectors are designed to produce proteins from cloned genes in host cells. Beyond basic cloning vector features, they include: strong promoters (T7, CMV, trc) for high transcription, ribosome binding sites (Shine-Dalgarno in prokaryotes, Kozak in eukaryotes) for efficient translation, terminators for proper transcription ending, and often fusion tags for detection and purification (His-tag, GST, FLAG). Inducible promoters (lac, tet, araBAD) allow controlled expression. Signal sequences direct secretion. The choice of vector depends on the host system (bacterial, yeast, mammalian, insect) and protein requirements.