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Reverse transcriptase an enzyme. Diversity generating reverse transcriptase. BPP Substitutions in action. Reverse transcriptase. Phage tail fiber. Unknown protein. Directed by initiation of mutagenic homing. Alignment of BPP's VR vs TR. 1 in every million replications. BMP. BIP.
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Reverse transcriptase an enzyme Diversity generating reverse transcriptase
BPP Substitutions in action Reverse transcriptase Phage tail fiber Unknown protein Directed by initiation of mutagenic homing
BMP BIP
Not great identity but similar function Same Downstream order as in bordetella phages Unidentified protein VR Reverse Transcriptase Phage Tail fiber TR
TR VS VR in VHML What does it do??????????????
Vibrio phage with similar reverse transcriptase Vibrio phage with similar sequence but no reverse transcriptase
Understanding Phylogeny and Predicting New Class III Inteins Mobile Elements
Inteins – What are they? Introns Inteins
Classes of Inteins(per splicing mechanism) Begins withSer, Thr, or Cys HX amino acid HO-… SerineHO-CH3-…ThreonineHS-CH3-… Cysteine Tori et al (2010). J Biol Chem 285:2515-2526
Classes of Inteins(per splicing mechanism) Class I Class II Begins withSer, Thr, or Cys Doesn't begin withSer, Thr, or Cys HX amino acid HO-… SerineHO-CH3-…ThreonineHS-CH3-… Cysteine Tori et al (2010). J Biol Chem 285:2515-2526
Classes of Inteins(per splicing mechanism) Class I Class II Class III Begins withSer, Thr, or Cys Doesn't begin withSer, Thr, or Cys Uses embeddedSer, Thr, orCys HX amino acid HO-… SerineHO-CH3-…ThreonineHS-CH3-… Cysteine Tori et al (2010). J Biol Chem 285:2515-2526
Classes of Inteins(per splicing mechanism) Class I Class II Class III Begins withSer, Thr, or Cys Doesn't begin withSer, Thr, or Cys Uses embeddedSer, Thr, orCys How to recognize classes by sequence characteristics? Tori et al (2010). J Biol Chem 285:2515-2526
Recognition by conserved amino acid residues. Histidine Asparagine Histidine Glycine Glycine G G H H N C T W Cysteine Threonine Tryptophan
What about extien similarity? ????????? DnaB Intein Jumped in here? Known inteins
Acknowledgements. This work would not have been possible without the support of: • Jeff Elhai • RaihaTahir • Mobile Elements Group
Mobile elements existence in mycobacteriophages Farah DahmanBioinformatics 301
How to know if mobile element found • 5′-TTATC[a/t]GGGGT-3’MPEME1MPEME2 “Mycobacteriophages BPs, Angel and Halo: comparative genomics reveals a novel class of ultra-small mobile genetic elements.”
Method • Phages studied: Cluster F (average length- 57,422bp)Fruit Loop, DotProduct, Ramsey, Yoshi, Boomer
Method • Run mobile element sequence through biobike into each bacteriophage TTATC[a/t]GGGGT • Find closest match
Exact matches found in FruitLoop, Boomer, Yoshi Each has some form of end part of sequence, but not the TTAT piece Relatively close proximity of match within sequence compared to others Phages of Cluster F do share the same ultra small mobile elements