7vii

From Proteopedia

cryoEM structure of bacteriophage lambda capsid at 5.6 Angstrom

7vii, resolution 5.60Å

Structural highlights

7vii is a 14 chain structure with sequence from Escherichia virus Lambda. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 5.6Å
Experimental data:	Check to display Experimental Data
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CAPSD_LAMBD Assembles to form an icosahedral capsid with a T=7 symmetry. The icosahedral capsid is about 60 nm in diameter and composed of 415 major capsid proteins. The assembly is primed by the interaction between capsid assembly protease and portal dodecamer, and major capsid proteins assemble cooperatively to form the procapsid with the help of capsid scaffolding protein. Major capsid protein forms hexons and pentons of the icosahedron. Viral genomic DNA is packaged into the procapsid through the portal vertex (By similarity). The packaging triggers a dramatic reconfiguration of the capsid shell, expanding from roughly 50nm to 60nm while the capsid thickness decreases. The capsid decoration protein binds the expanded capsid and stabilizes it.[HAMAP-Rule:MF_04133]^[1] ^[2] ^[3]

Publication Abstract from PubMed

Bacteriophage lambda is an excellent model system for studying capsid assembly of double-stranded DNA (dsDNA) bacteriophages, some dsDNA archaeal viruses, and herpesviruses. HK97 fold coat proteins initially assemble into a precursor capsid (procapsid) and subsequent genome packaging triggers morphological expansion of the shell. An auxiliary protein is required to stabilize the expanded capsid structure. To investigate the capsid maturation mechanism, we determined the cryo-electron microscopy structures of the bacteriophage lambda procapsid and mature capsid at 3.88 A and 3.76 A resolution, respectively. Besides primarily rigid body movements of common features of the major capsid protein gpE, large-scale structural rearrangements of other domains occur simultaneously. Assembly of intercapsomers within the procapsid is facilitated by layer-stacking effects at 3-fold vertices. Upon conformational expansion of the capsid shell, the missing top layer is fulfilled by cementing the gpD protein against the internal pressure of DNA packaging. Our structures illuminate the assembly mechanisms of dsDNA viruses.

Structural basis of bacteriophage lambda capsid maturation.,Wang C, Zeng J, Wang J Structure. 2022 Jan 4. pii: S0969-2126(21)00461-5. doi:, 10.1016/j.str.2021.12.009. PMID:35026161^[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Katsura I, Kobayashi H. Structure and inherent properties of the bacteriophage lambda head shell. VII. Molecular design of the form-determining major capsid protein. J Mol Biol. 1990 Jun 5;213(3):503-11. doi: 10.1016/S0022-2836(05)80211-6. PMID:2141087 doi:http://dx.doi.org/10.1016/S0022-2836(05)80211-6
↑ Murialdo H, Becker A. Assembly of biologically active proheads of bacteriophage lambda in vitro. Proc Natl Acad Sci U S A. 1977 Mar;74(3):906-10. doi: 10.1073/pnas.74.3.906. PMID:265585 doi:http://dx.doi.org/10.1073/pnas.74.3.906
↑ Dokland T, Murialdo H. Structural transitions during maturation of bacteriophage lambda capsids. J Mol Biol. 1993 Oct 20;233(4):682-94. PMID:8411174 doi:http://dx.doi.org/10.1006/jmbi.1993.1545
↑ Wang C, Zeng J, Wang J. Structural basis of bacteriophage lambda capsid maturation. Structure. 2022 Jan 4. pii: S0969-2126(21)00461-5. doi:, 10.1016/j.str.2021.12.009. PMID:35026161 doi:http://dx.doi.org/10.1016/j.str.2021.12.009