Skip to main content
. 2019 Aug 15;10(3):23–31.

Table 3.

β-galactosidase missense mutants

lacZ mutant Amino acid change1 Structural perturbation2 Mutation favorability3 Protein Location4 Change in hydropathy5 Salt Suppressible
39 1018 Leu to Gln Beta Sheet - Surface (Partial) +* +
337 905 Glu to Lys Coil + Surface (Partial) + +
361 900 Gly to Asp Beta Sheet - Buried +* -
364 208 Gly to Asp Beta Sheet - Buried +* +
2234 565 Gly to Asp Beta Sheet - Buried +* +
2343 943 Arg to His Beta Sheet + Surface -* +
2381 764 Gly to Asp Coil - Buried +* +
2382 566 Gly to Asp Beta Sheet - Buried +* -
2396 584 Gly to Asp Coil - Surface +* +
2449 202 Asp to Asn Coil + Surface (Partial) - +
2454 354 Gly to Asp Beta Sheet - Buried +* -
2456 5 Thr to Met Alpha Helix +* Surface -* +
2530 419 His to Tyr Coil -* Surface - +
2540 4 Ile to Asn Alpha Helix -* Surface +* +
2608 460 Gly to Arg Coil -* Buried +* -
1

The lacZ gene codes for the 1,024 amino acid β-galactosidase protein. The resulting amino acid changes are given based on the coded protein predicted by the DNA sequence and not the Protein Data Bank file.

2

The secondary structure affected by the mutation was determined using PyMol. Data from Jacobson et al. [23] had to be used to determine the secondary structures affected by lacZ2456 and lacZ2540, since these mutations were at the extreme amino terminus.

3

The likelihood of a mutation to affect the α-helical, β-sheet or random coil structure was determined using Pα, Pβ or Pc values from the averaged propensity scale in Cole et al. [20]. (+) indicates a favorable change and (-) indicates an unfavorable change. An asterisk indicates a mutation that changes the original amino acid from or to one of the preferred amino acids that are found in α-helices, β-sheets or random coils.

4

The location of the mutated amino acids was determined using PyMOL.

5

The change in hydropathy was determined using the averaged hydrophobicity scale from Cole et al. [20]. (+) indicates a more hydrophilic change, (-) indicates a more hydrophobic change. An asterisk indicates a mutation that changes the hydropathy of the original amino acid significantly and results in a shift of at least 5 amino acids.