Bacteriophage pRNA

{{Infobox rfam

| Name = Bacteriophage pRNA

| image = RF00044.jpg

| width =

| caption = Predicted secondary structure and sequence conservation of Phage_pRNA

| Symbol = Phage_pRNA

| AltSymbols =

| Rfam = RF00044

| miRBase =

| miRBase_family =

| RNA_type = Gene

| Tax_domain = Viruses

| GO =

| SO = {{SO|0000655}}

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| EntrezGene =

| HGNCid =

| OMIM =

| PDB =

| RefSeq =

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| Arm =

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}}

Bacteriophage pRNA is a ncRNA element. During replication of linear dsDNA viruses, the viral genome is packaged into the pre-formed viral procapsid. The packaging of DNA into the procapsid requires a molecular motor, which uses ATP as energy to accomplish the energetically unfavorable motion. In some bacteriophage, an RNA (pRNA) molecule is a vital component of this motor.{{cite journal |author=Guo P |title=Structure and function of phi29 hexameric RNA that drives the viral DNA packaging motor: review |journal=Prog Nucleic Acid Res Mol Biol. |volume=72 |pages=415–472 |year=2002 |pmid=12206459 |doi=10.1016/S0079-6603(02)72076-X |isbn=978-0-12-540072-5}} Structural analyses of the packaging motor have demonstrated that the pRNA molecule has fivefold symmetry when attached to the prohead.{{cite journal |vauthors=Morais MC, Tao Y, Olson NH |title=Cryoelectron-microscopy image reconstruction of symmetry mismatches in bacteriophage phi29 |journal=J. Struct. Biol. |volume=135 |issue=1 |pages=38–46 |year=2001 |pmid=11562164 |pmc=5595366 |doi=10.1006/jsbi.2001.4379|display-authors=etal}}{{cite journal |vauthors=Simpson AA, Tao Y, Leiman PG |title=Structure of the bacteriophage phi29 DNA packaging motor |journal=Nature |volume=408 |issue=6813 |pages=745–750 |year=2000 |pmid=11130079 |doi=10.1038/35047129|display-authors=etal|pmc=4151180 |bibcode=2000Natur.408..745S }} The pRNA is thought to be bound by the capsid connector protein.{{cite journal |vauthors=Badasso MO, Leiman PG, Tao Y |title=Purification, crystallization and initial X-ray analysis of the head-tail connector of bacteriophage phi29 |journal=Acta Crystallogr. D |volume=56 |issue=Pt 9 |pages=1187–1190 |year=2000 |pmid=10957642 |doi=10.1107/S0907444900009239|display-authors=etal}} Only the first 120 bases of the pRNA are essential for packing the viral DNA.{{cite journal |vauthors=Guo PX, Erickson S, Anderson D |title=A small viral RNA is required for in vitro packaging of bacteriophage phi 29 DNA |journal=Science |volume=236 |issue=4802 |pages=690–694 |year=1987 |pmid=3107124 |doi=10.1126/science.3107124|bibcode=1987Sci...236..690G }} The pRNA is proposed to be composed of two domains, one corresponding to the first 120 bases and the second to the remaining 50 bases. Nuclear cleavage occurs in the single strand region linking these two domains.{{cite journal |vauthors=Bailey S, Wichitwechkarn J, Johnson D, Reilly BE, Anderson DL, Bodley JW |title=Phylogenetic analysis and secondary structure of the Bacillus subtilis bacteriophage RNA required for DNA packaging |journal=J. Biol. Chem. |volume=265 |issue=36 |pages=22365–22370 |year=1990 |doi=10.1016/S0021-9258(18)45714-6 |pmid=2125049 |doi-access=free }}