[lee-usmle]

Palindromes are DNA sequences recognized by restriction endonucleases.
They are 4 to 8 bases in length
They mirror image (base pairs) if one draws an imaginary line in the middle

Examples

CTGCAG
TAAGCTTA
GTAC

Note for example in sequence one above the first C can be paired with the last C and the second T can be paired with the 5th A and the third base G can be paired with the 4hth base C

Fold the paper in the middle and they should match

Note that restriction endonucleases recognize the sequence which we have recognized by folding the middle but they do not necessarily cut it in the middle, they may cut it obliquely yielding sticky ends or may cut it exactly in the middle yielding blunt ends.
For example here's a double stranded Palindrome cut into sticky ends

CTGCAG
GACGTC

cut to

C---TGCAG
GACGT---C

This is a common USMLE question

 

[wahaha007]

Concerning the last G not C!!!

here (Note for example in sequence one above the first C can be paired with the last C and the second T can be paired with the 5th A and the third base G can be paired with the 4hth base C

Fold the paper in the middle and they should match....)
The first C can be paired with the last G (not the last C). Right ?

 

[lee-usmle]

here (Note for example in sequence one above the first C can be paired with the last C and the second T can be paired with the 5th A and the third base G can be paired with the 4hth base C

Fold the paper in the middle and they should match....)
The first C can be paired with the last G (not the last C). Right ?

Yes, the first C will pair with the last G on the same strand. Palindromes make pairing among adjacent bases on the same strand (not with the complimentary strands).

 

[usmleman2020]

cooooooooooooooooooooolllllllllllllllllllllllllllllll!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!