2B83

A single amino acid substitution in the Clostridium beijerinckii alcohol dehydrogenase is critical for thermostabilization

Summary for 2B83

• Entry DOI: 10.2210/pdb2b83/pdb
• Related: 1JQB
• Descriptor: NADP-dependent alcohol dehydrogenase, ZINC ION (3 entities in total)
• Functional Keywords: cbadh mutant, metal binding, structural genomics, israel structural proteomics center, ispc, oxidoreductase
• Biological source: Clostridium beijerinckii
• Total number of polymer chains: 4
• Total formula weight: 151189.14

Authors

Goihberg, E.,Dym, O.,Israel Structural Proteomics Center (ISPC) (deposition date: 2005-10-06, release date: 2006-09-19, Last modification date: 2023-08-23)

Primary citation

Goihberg, E.,Dym, O.,Tel-Or, S.,Levin, I.,Peretz, M.,Burstein, Y.
A single proline substitution is critical for the thermostabilization of Clostridium beijerinckii alcohol dehydrogenase.
Proteins, 66:196-204, 2006

PubMed Abstract: Analysis of the three-dimensional structures of three closely related mesophilic, thermophilic, and hyperthermophilic alcohol dehydrogenases (ADHs) from the respective microorganisms Clostridium beijerinckii (CbADH), Entamoeba histolytica (EhADH1), and Thermoanaerobacter brockii (TbADH) suggested that a unique, strategically located proline residue (Pro100) might be crucial for maintaining the thermal stability of EhADH1. To determine whether proline substitution at this position in TbADH and CbADH would affect thermal stability, we used site-directed mutagenesis to replace the complementary residues in both enzymes with proline. The results showed that replacing Gln100 with proline significantly enhanced the thermal stability of the mesophilic ADH: DeltaT(1/2) (60 min) = + 8 degrees C (temperature of 50% inactivation after incubation for 60 min), DeltaT(1/2) (CD) = +11.5 degrees C (temperature at which 50% of the original CD signal at 218 nm is lost upon heating between 30 degrees and 98 degrees C). A His100 --> Pro substitution in the thermophilic TbADH had no effect on its thermostability. An analysis of the three-dimensional structure of the crystallized thermostable mutant Q100P-CbADH suggested that the proline residue at position 100 stabilized the enzyme by reinforcing hydrophobic interactions and by reducing the flexibility of a loop at this strategic region.

PubMed: 17063493
DOI: 10.1002/prot.21170

Experimental method

X-RAY DIFFRACTION (2.25 Å)