Source 1primary paper2007Biochemistry
Toolkit/EF-IV domain of CIB1
EF-IV domain of CIB1
Also known as: EF-IV, F173W
Taxonomy: Mechanism Branch / Component. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
EF-IV is the C-terminal EF-hand IV region of calcium- and integrin-binding protein 1 (CIB1), represented here with the F173W variant. Available evidence indicates that this region is partially unfolded and dynamic in apo CIB1, and becomes more ordered in Mg2+-bound CIB1 while retaining some conformational heterogeneity.
Usefulness & Problems
Why this is useful
This domain is useful as a defined structural element for studying metal-dependent conformational changes within CIB1. The available evidence supports its relevance to analyses of folding, disorder-to-order transitions, and residual heterogeneity in the C-terminal EF-IV region.
Problem solved
EF-IV helps address the problem of identifying which CIB1 regions undergo metal-dependent stabilization versus dynamic partial unfolding. Specifically, the evidence links EF-IV to a partially unfolded apo state and a more folded Mg2+-bound state.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Component: A low-level protein part used inside a larger architecture that realizes a mechanism.
Mechanisms
conformational uncagingconformational uncagingConformational Uncagingmetal-induced foldingmetal-induced foldingTechniques
No technique tags yet.
Target processes
No target processes tagged yet.
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationoperating role: actuatorswitch architecture: uncaging
The evidence refers to the EF-IV region of CIB1 and explicitly mentions the F173W variant. Metal state is a key experimental variable, with apo and Mg2+-bound conditions producing different conformational behaviors; no additional construct design, expression, or delivery details are provided.
Evidence is limited to structural-state observations from a single cited study and does not establish this domain as a standalone engineered actuator or reporter. No direct functional outputs, kinetics, photoregulation, binding partners, or application-specific performance data are provided.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
Apo-CIB1 is significantly more dynamic, especially within EF-II, EF-III, and a partially unfolded EF-IV region.
The structure of apo-CIB1 is significantly more dynamic, especially within EF-II, EF-III, and a partially unfolded EF-IV region
Mg2+-bound CIB1 adopts a well-folded structure similar to Ca2+-bound CIB1, with some conformational heterogeneity in the C-terminal EF-IV domain.
We find that Mg2+-CIB1 adopts a well-folded structure similar to Ca2+-CIB1, except for some conformational heterogeneity in the C-terminal EF-IV domain.
Approval Evidence
1 source2 linked approval claimsfirst-pass slug ef-iv-domain-of-cib1
EF-IV (F173W)
Source:
structural dynamicssupports
Apo-CIB1 is significantly more dynamic, especially within EF-II, EF-III, and a partially unfolded EF-IV region.
The structure of apo-CIB1 is significantly more dynamic, especially within EF-II, EF-III, and a partially unfolded EF-IV region
Source:
structural statesupports
Mg2+-bound CIB1 adopts a well-folded structure similar to Ca2+-bound CIB1, with some conformational heterogeneity in the C-terminal EF-IV domain.
We find that Mg2+-CIB1 adopts a well-folded structure similar to Ca2+-CIB1, except for some conformational heterogeneity in the C-terminal EF-IV domain.
Source:
Comparisons
Source-backed strengths
The available study directly attributes distinct structural states to EF-IV under different metal conditions, supporting a metal-responsive conformational role. EF-IV is specifically noted as partially unfolded in apo CIB1 and still conformationally heterogeneous even when Mg2+ binding promotes an overall well-folded structure.
Compared with AUREO1 LOV-only construct
EF-IV domain of CIB1 and AUREO1 LOV-only construct address a similar problem space.
Shared frame: same top-level item type; shared mechanisms: conformational_uncaging
Strengths here: looks easier to implement in practice.
Compared with CIB1 helix 10 pocket
EF-IV domain of CIB1 and CIB1 helix 10 pocket address a similar problem space.
Shared frame: same top-level item type; shared mechanisms: conformational uncaging, conformational_uncaging
Compared with LOV2 domain C450A variant
EF-IV domain of CIB1 and LOV2 domain C450A variant address a similar problem space.
Shared frame: same top-level item type; shared mechanisms: conformational uncaging, conformational_uncaging
Ranked Citations
- 1.