Question

Make a conceptual map of the different types of vectors and their characteristics in molecular biology. Add bibliography, not Wikipedia

Answer 1

Most common bacterial plasmid architectures and categories.A. On the top, a minimal general architecture is formed by an origin of replication (ori), an antibiotic resistance marker (Ab ^R) and a multiple cloning site (MCS). From this general architecture, vectors can be categorized as narrow‐host‐range, broad‐host‐range and shuttle vectors. In the case of narrow‐host‐range, the ori relays on the replication machinery or a protein (Rep) provided by the host. In the case of broad‐host‐range vectors, the plasmid harbours its own Rep gene, which makes it mostly host‐independent. In the case of shuttle vectors, two ori regions (ori1 and ori2) are placed in the vector, each one being recognized by a specific Rep protein from different hosts (Rep1 and Rep2). In addition to that, two Ab^R (Ab^R 1 and Ab^R 2) are introduced to allow the selection in the appropriate host.B. Different functionalities of vectors. In cloning vectors, a MCS is usually located within a selection marker (such as the lacZα gene in pUC vectors) to allow the easy identification of plasmids with inserted fragments. In expression vectors, the MCS is preceded by an expression system (here shown as a regulated promoter P and its cognate regulator R) that allows the expression of the cloned fragment in response to a chemical inducer. Additionally, a strong terminator signal (Ter) is located after the MCS to ensure efficient transcriptional termination and increased plasmid stability. Finally, in a reporter vector, a reporter gene (such as a fluorescent protein, a luciferase coding gene or an enzyme‐coding gene such as lacZ) is flanked by an MCS and a strong terminator. In this system, the cloning of a promoter sequence in the MCS allows the investigation of promoter dynamics using the reporter gene of choice.