Question

In a footprinting assay, you use dsDNA that is 16bp long. Here is the sequence of the top

strand: 5’TTTTGCGCTTTTAGAG. The restriction enzyme MSpI binds to the GCGC sequence.

What would a footprint look like if the strand above has a single 32P group on the 5’ end? Draw

your autoradiogram results clearly showing the sequence of each fragment/band on the gel. (2

lanes: + MSpI and - MSpI). Now, what would happen if every phosphate in the top strand was

radioactive? Do you get a footprint? Explain.

Answer 1

tmspil-paspi MѕР | — м31 1 1 Puso is When, only stand radio-talolled hen, al phosphate. it radio doclled,

S TTTTG cGc TTTTAGA, 3" 2 AAAAcGcA A A Aтстс s' After Treatment with Mapa ѕ ттттеге тттт AG AG ! G A A A Tc Tc ! A AAA S TTC GcTTTTA GAG 3' А А А А се сбANA татс " 2
because this chain will be cleaved by restriction endonuclease and produces 2 strand one of length 6 no which will be autoradiography because it will only contain the radioisotopes phosphorus

And another of 1pbp will not give emission.

If all phosphate are radiosotyoes then, both the 10 and 6 no will give signal when present with MSP1 AND WILL GIVE ONE lenGTH OF 16 WHEN NO MSP1 IS PRESENT.THANK YOU A LOT