Force required to package DNA in capsid

Value 57 pN
Organism Bacteriophage phi 29
Reference Smith DE, Tans SJ, Smith SB, Grimes S, Anderson DL, Bustamante C. The bacteriophage straight phi29 portal motor can package DNA against a large internal force.Nature. 2001 Oct 18413(6857):748-52.PubMed ID11607035
Method Force-measuring laser tweezers are used to follow packaging activity of a single complex in real time. Stalled, partly prepackaged complexes are attached to a polystyrene microsphere by means of the unpackaged end of the DNA. This microsphere is captured in the optical trap and brought into contact with a second bead that is held by a pipette. This bead is coated with antibodies against the phage, so a stable tether is formed between the two beads
Comments pN=picoNewton=10^-12Newton.
Entered by Uri M
ID 103126