Upload
keegan-snowdon
View
213
Download
0
Tags:
Embed Size (px)
Citation preview
The 20 amino acids
A Ala AlanineSmallHydrophobic
Helix: ++Strand: –Turn: – –
Mutate to Ala if you have to mutate but have no clue to which residue
C Cys CysteineSmallHydrophobicSulfur containing
Helix: –Strand: +Turn: +
The SH-group is very reactive:Can make Cys-Cys bridgesCan bind metal ions (especially Zn and Cu)
D Asp AspartateIntermediately largeHydrophilicNegatively charged
Helix: 0 (++ at N-terminus)Strands: – –Turn: ++
Often in active sitesCan bind ions (mainly calcium)
E Glu GlutamateLargeHydrophilicNegatively charged
Helix: ++Strand: 0Turn: –
F Phe PhenylalanineLargeHydrophobicAromatic
Helix: 0Strand: ++Turn: – –
G Gly GlycineSmallest residueNo side chain
Hydrophobicity undeterminedVery flexibleStar of the turn
Helix: – –Strand: –Turn: ++
H His HistidineLargeHydrophilicCharge (depending on the environment):
PositiveNeutral or Negative
No secondary structure preference
Often in active sitesCan bind metal ions (mainly Zn, Ni, Cu)
I Ile IsoleucineIntermediately largeHydrophobic
Helix: 0Strand: ++Turn: – –
K Lys LysineLargeHydrophilicPositively charged
Helix: ++Strand: –Turn: 0
Long, flexible side chain
L Leu LeucineIntermediately largeHydrophobic
Helix: ++Strand: +Turn: – –
M Met MethionineLargeHydrophobicSulfur containing
Helix: ++Strand: 0Turn: – –
Non-reactive sulfur which can bind metal ionsOften the first residue of the sequence
Intermediately largeHydrophilic
Helix: – –Strand: 0Turn: ++
Can bind ions (Ca) but not as well as its isosteric partner Asp
N Asn Asparagine
P Pro ProlineSmallHydrophobic
Helix: – – (except at the first position)Strand: – –Turn: ++
Imino acidNo backbone protonPre-bend for turns
Q Gln GlutamineLargeHydrophilic
Helix: +Strand: 0Turn: 0
Isosteric with Glu
LargeHydrophilicPositively charged
No secondary structure preference
Contains a rigid guanidinium group
R Arg Arginine
S Ser SerineSmallIntermediate hydrophobicityAlcoholic
Helix: –Strand: –Turn: ++
Often in active sites (with Asp and His)Can bind calcium
T Thr ThreonineSmallIntermediate hydrophobicityAlcoholic
Helix: 0Strand: +Turn: 0
Can bind calcium
V Val ValineSmallHydrophobic
Helix: 0Strand: ++Turn: – –
Isosteric with Thr
W Trp TryptophanLargest residueHydrophobicAromatic
Helix: 0Strand: ++Turn: 0
Most conserved residue
Y Tyr TyrosineLargeIntermediate hydrophobicityAromaticAlcoholic
Helix: –Strand: ++Turn: 0