Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Two new examples of protein structural similarities within the structure-function twilight zone

R B Russell1, M J Sternberg

  • 1Biomolecular Modelling Laboratory, Imperial Cancer Research Fund, London, UK.

Protein Engineering
|April 1, 1997
PubMed
Summary

Protein structure and function relationships are complex. Two examples show similar protein structures with minor functional overlaps, illustrating challenges in discerning evolutionary links and protein evolution.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The mutational pattern of primary lymphoma of the central nervous system determined by whole-exome sequencing.

Leukemia·2014
Same author

Hb M Dothan [beta 25/26 (B7/B8)/(GGT/GAG-->GAG//Gly/Glu-->Glu]; a new mechanism of unstable methemoglobin variant and molecular characteristics.

Blood cells, molecules & diseases·2009
Same author

Enhancement of protein modeling by human intervention in applying the automatic programs 3D-JIGSAW and 3D-PSSM.

Proteins·2002
Same author

Fold recognition from sequence comparisons.

Proteins·2002
Same author

Predicting function from structure: examples of the serine protease inhibitor canonical loop conformation found in extracellular proteins.

Computers & chemistry·2002
Same author

Generating protein three-dimensional fold signatures using inductive logic programming.

Computers & chemistry·2002

Area of Science:

  • Biochemistry
  • Structural Biology
  • Protein Science

Background:

  • Discerning the relationship between protein structure and function is a significant challenge in molecular biology.
  • Protein structural similarities can sometimes be misleading regarding functional relationships, existing in a 'twilight zone'.

Purpose of the Study:

  • To highlight the difficulties in determining protein relationships by presenting two cases of structural similarity with functional overlap.
  • To discuss the implications of these findings for understanding protein evolution and the structure-function paradigm.

Main Methods:

  • Comparative analysis of three-dimensional protein structures.
  • Identification of common structural motifs (e.g., four-helix bundle, beta-barrel).
  • Functional analysis to assess similarities in binding sites and biochemical roles.

Related Experiment Videos

Main Results:

  • Uteroglobin and the CAP domain of haloalkane dehalogenase share a common four-helix hydrophobic ligand-binding motif.
  • Glutaminyl tRNA synthetase and glutamine synthetase share beta-barrel domains with similar nucleotide-binding site locations, suggesting a common ancestral domain.
  • These similarities present challenges in classifying protein relationships based solely on structure or function.

Conclusions:

  • Structural similarities alone are insufficient to definitively establish functional or evolutionary relationships between proteins.
  • The 'twilight zone' of protein similarity complicates the interpretation of evolutionary history and protein classification.
  • Further investigation is needed to refine methods for distinguishing convergent evolution from divergent evolution in proteins.