[net.origins] Biochemical Relatedness

rlp@cbosgd.UUCP (Bob Platt) (07/06/85)

The following table (from "Human Biology and Behavior" Little 1975) shows
some interesting biochemical similarities among primates in their 
"beta hemoglobin chains." The table shows the amino acid located at each
position in the chain (only the variable positions are shown). Differences
from the human chain appear in upper-case:

				     Position
Species            5   6   9  13  21  22  33  50  56  76  80  87 104 125
============     === === === === === === === === === === === === === ===
Human/Chimp      pro glu ser ala asp glu val thr gly ala asn thr arg pro

Gorilla          pro glu ser ala asp glu val thr gly ala asn thr LYS pro

Gibbon           pro glu ser ala asp glu val thr gly ala ASP LYS arg GLN

Rhesus monkey    pro glu ASN THR asp glu LEU SER gly ASN asn GLN LYS GLN

Squirrel monkey  GLY ASP ALA ala GLU ASP val thr ASN THR asn GLN arg GLN

A measure of the genetic distance between any two chains is the "minimum
mutation distance" or MMD. This is the fewest number of mutations that 
will transform one chain into the other. The MMD can be calculated with
the following table:

N=nucleotide= < U | C | A | G >
codon=genetic code word for an amino acid= NNN
one mutation=change of one nucleotide in a codon

First position   Second position   Third position

                 U   C   A   G
U                phe ser tyr cys		U
                 phe ser tyr cys		C
		 leu ser non non                A
		 leu ser non try                G
C                leu pro his arg		U
		 leu pro his arg		C
		 leu pro gln arg                A
		 leu pro gln arg		G
A		 ile thr asn ser		U
		 ile thr asn ser                C
		 ile thr lys arg		A
		 met thr lys arg		G
G		 val ala asp gly		U
		 val ala asp gly		C
		 val ala glu gly		A
		 val ala glu gly		G

For example, if the gorilla's codon at 104 changes from AAA to AAG, this
would amount to a change from lysine to argine. The MMD is then 1.

						Joe Knapp (cbosgd!nscs!jmk)