Transfer RNA-like structures
{{short description|RNA sequences similar in structure to tRNA, found in plant virus genomes}}
Transfer RNA-like structures (tRNA-like structures) are RNA sequences, which have a similar tertiary structure to tRNA; they frequently contain a pseudoknot close to the 3' end.{{cite journal |author=Dreher TW |title=Role of tRNA-like structures in controlling plant virus replication |journal=Virus Res. |volume= 139|issue= 2|pages= 217–229|date=July 2008 |pmid=18638511 |doi=10.1016/j.virusres.2008.06.010 |pmc=2676847}} The presence of tRNA-like structures has been demonstrated in many plant virus RNA genomes. These tRNA-like structures are linked to regulation of plant virus replication.
tRNA-like structures mimic some tRNA function, such as aminoacylation. There are three aminoacylation specificities, valine, histidine and tyrosine. For example, valine binds to the tRNA-like structure of the turnip yellow mosaic virus genome whilst tyrosine binds to the tRNA-like structure of the barley stripe mosaic virus genome.{{cite journal |vauthors=Mans RM, Pleij CW, Bosch L |title=tRNA-like structures. Structure, function and evolutionary significance |journal=Eur. J. Biochem. |volume=201 |issue=2 |pages=303–324 |date=October 1991 |pmid=1935928 |doi=10.1111/j.1432-1033.1991.tb16288.x |doi-access=free }} tRNA-like structures which lack the 3' termini lack complete or partial tRNA mimicry.
tRNA-like structures are required for RNA encapsulation and increase RNA stability. They also act as 3'-translational enhancers{{cite journal |vauthors=Matsuda D, Dreher TW |title=The tRNA-like structure of Turnip yellow mosaic virus RNA is a 3'-translational enhancer |journal=Virology |volume=321 |issue=1 |pages=36–46 |date=March 2004 |pmid=15033563 |doi=10.1016/j.virol.2003.10.023 |doi-access=free }} and regulators of minus strand synthesis.
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| Image:TLS-PK1_secondary_structure.jpg|TLS-PK1: Secondary structure taken from the [http://rfam.org Rfam] database. Family [http://rfam.org/family/RF01075 RF01075]. Derived from Pseudobase [http://www.ekevanbatenburg.nl/PKBASE/PKB00138.HTML PKB00138] [http://www.ekevanbatenburg.nl/PKBASE/PKB00164.HTML PKB00164]
| Image:TLS-PK2_secondary_structure.jpg|TLS-PK2: Secondary structure taken from the [http://rfam.org Rfam] database. Family [http://rfam.org/family/RF01077 RF01077]. Derived from Pseudobase [http://www.ekevanbatenburg.nl/PKBASE/PKB00139.HTML PKB00139] [http://www.ekevanbatenburg.nl/PKBASE/PKB00057.HTML PKB00057]
| Image:TLS-PK3_secondary_structure.jpg|TLS-PK3: Secondary structure taken from the [http://rfam.org Rfam] database. Family [http://rfam.org/family/RF01084 RF01084]. Derived from Pseudobase [http://www.ekevanbatenburg.nl/PKBASE/PKB00134.HTML PKB00134] [http://www.ekevanbatenburg.nl/PKBASE/PKB00136.HTML PKB00136] [http://www.ekevanbatenburg.nl/PKBASE/PKB00137.HTML PKB00137].
| Image:TLS-PK4_secondary_structure.jpg|TLS-PK4: Secondary structure taken from the [http://rfam.org Rfam] database. Family [http://rfam.org/family/RF01085 RF01085]. Derived from Pseudobase [http://www.ekevanbatenburg.nl/PKBASE/PKB00135.HTML PKB00135]
| Image:TLS-PK5_secondary_structure.jpg|TLS-PK5: Secondary structure taken from the [http://rfam.org Rfam] database. Family [http://rfam.org/family/RF01088 RF01088]. Derived from Pseudobase [http://www.ekevanbatenburg.nl/PKBASE/PKB00143.HTML PKB00143]
| Image:TLS-PK6_secondary_structure.jpg|TLS-PK6: Secondary structure taken from the [http://rfam.org Rfam] database. Family [http://rfam.org/family/RF01101 RF01101]. Derived from Pseudobase [http://www.ekevanbatenburg.nl/PKBASE/PKB00130.HTML PKB00130]
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