Abstract
Some double-stranded DNA bacteriophages consist of DNA packaged in a proteinaceous capsid. The capsid has a DNA-enclosing outer shell (head) attached to an external projection (tail). At the head-tail junction is a ring of subunits (connector) that has either six or twelve-fold rotational symmetry, and is joined to the head at an axis of the head's five-fold rotational symmetry. The head is made of subunits in either an icosahedral array or an array consisting of two icosahedral hemispheres separated by a cylinder of subunits. During infection of a host, the head with connector is assembled as a procapsid that subsequently packages DNA and joins a tail. The mechanism for producing two symmetries at the head-tail junction has in the past been an unsolved problem. The observation that the connector of bacteriophage T7 does not nucleate asembly of the outer shell of T7's icosahedral procapsid (P. Serwer and R. H. Watson [1982] J. Virol. 42, 595-601) places a constraint on a solution for the above problem. To solve the above problem for icosahedral procapsids, it is proposed here that: (a) assembly of the outer shell of procapsids is nucleated by a six-membered ring of hexameric aggregates of the major outer shell protein, (b) the connector is assembled in the center of this ring, (c) one of the hexamers dissociates from the ring, creating a five-membered ring and forcing the connector to the inside of the outer shell. A related mechanism is proposed for nucleation of the elongated procapsid of bacteriophage T4.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 155-161 |
| Number of pages | 7 |
| Journal | Journal of Theoretical Biology |
| Volume | 127 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jul 21 1987 |
Fingerprint
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)
- Applied Mathematics
- Modeling and Simulation
- Statistics and Probability
- Medicine(all)
Cite this
The mechanism for producing two symmetries at the head-tail junction of bacteriophages : a hypothesis. / Serwer, Philip.
In: Journal of Theoretical Biology, Vol. 127, No. 2, 21.07.1987, p. 155-161.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The mechanism for producing two symmetries at the head-tail junction of bacteriophages
T2 - a hypothesis
AU - Serwer, Philip
PY - 1987/7/21
Y1 - 1987/7/21
N2 - Some double-stranded DNA bacteriophages consist of DNA packaged in a proteinaceous capsid. The capsid has a DNA-enclosing outer shell (head) attached to an external projection (tail). At the head-tail junction is a ring of subunits (connector) that has either six or twelve-fold rotational symmetry, and is joined to the head at an axis of the head's five-fold rotational symmetry. The head is made of subunits in either an icosahedral array or an array consisting of two icosahedral hemispheres separated by a cylinder of subunits. During infection of a host, the head with connector is assembled as a procapsid that subsequently packages DNA and joins a tail. The mechanism for producing two symmetries at the head-tail junction has in the past been an unsolved problem. The observation that the connector of bacteriophage T7 does not nucleate asembly of the outer shell of T7's icosahedral procapsid (P. Serwer and R. H. Watson [1982] J. Virol. 42, 595-601) places a constraint on a solution for the above problem. To solve the above problem for icosahedral procapsids, it is proposed here that: (a) assembly of the outer shell of procapsids is nucleated by a six-membered ring of hexameric aggregates of the major outer shell protein, (b) the connector is assembled in the center of this ring, (c) one of the hexamers dissociates from the ring, creating a five-membered ring and forcing the connector to the inside of the outer shell. A related mechanism is proposed for nucleation of the elongated procapsid of bacteriophage T4.
AB - Some double-stranded DNA bacteriophages consist of DNA packaged in a proteinaceous capsid. The capsid has a DNA-enclosing outer shell (head) attached to an external projection (tail). At the head-tail junction is a ring of subunits (connector) that has either six or twelve-fold rotational symmetry, and is joined to the head at an axis of the head's five-fold rotational symmetry. The head is made of subunits in either an icosahedral array or an array consisting of two icosahedral hemispheres separated by a cylinder of subunits. During infection of a host, the head with connector is assembled as a procapsid that subsequently packages DNA and joins a tail. The mechanism for producing two symmetries at the head-tail junction has in the past been an unsolved problem. The observation that the connector of bacteriophage T7 does not nucleate asembly of the outer shell of T7's icosahedral procapsid (P. Serwer and R. H. Watson [1982] J. Virol. 42, 595-601) places a constraint on a solution for the above problem. To solve the above problem for icosahedral procapsids, it is proposed here that: (a) assembly of the outer shell of procapsids is nucleated by a six-membered ring of hexameric aggregates of the major outer shell protein, (b) the connector is assembled in the center of this ring, (c) one of the hexamers dissociates from the ring, creating a five-membered ring and forcing the connector to the inside of the outer shell. A related mechanism is proposed for nucleation of the elongated procapsid of bacteriophage T4.
UR - http://www.scopus.com/inward/record.url?scp=0023661754&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023661754&partnerID=8YFLogxK
U2 - 10.1016/S0022-5193(87)80126-1
DO - 10.1016/S0022-5193(87)80126-1
M3 - Article
C2 - 3695545
AN - SCOPUS:0023661754
VL - 127
SP - 155
EP - 161
JO - Journal of Theoretical Biology
JF - Journal of Theoretical Biology
SN - 0022-5193
IS - 2
ER -