Biochemistry Question

<< Is there anyway a proto tRNA with 2 codons - 1 at each end could hydrogen bond to a peptide bond
(and not at the side chain) ? If possible, I'm suggesting the fit should be almost perfect. >>

Later- I think I can pinpoint this 2nd anticodon area.

I see that a u-turn is in the anticodon but also in the TYC loop, that it begins not with a U but a
Y, then follows a C, a variable base, then A; for what I suggest is anticodon #2 so that

Anticodon #1 = 33 U = U turn 34 35 36 - all 3 anticodon

Now compare with TYC loop (at the top and virtually opposite anticodon

55 Y = u turn 56 - C 57 - variable (and this is the key one that like position 35 is the h -
bonder 58 - A

And note how similar this hidden anticodon is with the acceptor stem. C_A for the hidden one, and
CCA for the acceptor stem. May be a coincidence, may not

This is one curious molecue this tRNA. It seems more and more like two separate 2 loop molecules
joined together with an CCA stem tacked on later.

<< << Is there anyway a proto tRNA with 2 codons - 1 at each end could hydrogen bond to a peptide
bond (and not at the side chain) ? If possible, I'm suggesting the fit should be almost perfect. >>

Later- I think I can pinpoint this 2nd anticodon area.

I see that a u-turn is in the anticodon but also in the TYC loop, that it begins not with a U but a
Y, then follows a C, a variable base, then A; for what I suggest is anticodon #2 so that

Anticodon #1 = 33 U = U turn 34 35 36 - all 3 anticodon

Now compare with TYC loop (at the top and virtually opposite anticodon

55 Y = u turn 56 - C 57 - variable (and this is the key one that like position 35 is the h -
bonder 58 - A

And note how similar this hidden anticodon is with the acceptor stem. C_A for the hidden one, and
CCA for the acceptor stem. May be a coincidence, may not

This is one curious molecue this tRNA. It seems more and more like two separate 2 loop molecules
joined together with an CCA stem tacked on later. >>

Here is some more stuff that suggests this possible second anticodon on tRNA at 55-57

I found this on the tRNA, 56-58 bases that I suggest may have been a 2nd anticodon

1. " The bases,56,57,58 point to the opposite direction with respect to the 3 bases preceeding the U
turn." Just as in the anticodon.

2. "In each case the U turn is stabilized through interactions between the uridine residue and the
phosphate oxygen 3 residues downstream toward 3' terminus , U33 and Y55 interact p36, p58
respectively.

3. the purine on the 3' side of anticodon is typically modified. This modified purine base Y37
(though my chart shows A) may assist in interaction between anticodon and codon. In the 2nd
anticodon U -59 follows.