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A complex of proteins that bind with primase at specific sequences of DNA that serve as the sites for the formation of RNA primers; a part of the replisome.
[primer + -some]
Farlex Partner Medical Dictionary © Farlex 2012


(prī′mŏ-sōm″) [L. prim(ordium) + Gr. soma, body]
A multiprotein structure that makes RNA priming molecules during the replication of DNA. The primosome moves down DNA in a 3' to 5' direction.
Medical Dictionary, © 2009 Farlex and Partners


a complex of proteins, including the enzymes HELICASE and PRIMASE, involved in replication of some genomes, such as the CHROMOSOME of ESCHERICHIA COLI and of the BACTERIOPHAGE (|)X174.

The primosome moves along the single-stranded DNA, on the lagging strand, promoting the formation of RNA PRIMERS at the replicating fork (see DNA (b) REPLICATION).

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
coli 70S ribosome, DNA polymerase Pol [alpha]-B subunit complex of the eukaryotic primosome, and Tomato Bushy Stunt Virus was described more extensively with HEMNMA than with other methods [30].
(c, d) EM density map of a DNA polymerase Pol a-B subunit complex of the eukaryotic primosome from [59] (c) and a displacement of pseudoatoms along the normal mode describing the bending-unbending motion that has also been observed experimentally [30, 59] (d).
(a) EM density maps of three conformations of a DNA polymerase Pol [alpha]-B subunit complex of the eukaryotic primosome showing bending-unbending motion of the complex and the percentage of images assigned to each density map using ML3D, a method that assumes a small number of different coexisting conformations in the specimen, from [59].