Actin polymerization is controlled by residue size at position 204
Bibliographic record
Abstract
Previous work has shown that purified double mutant A204C/C374A yeast actin is polymerization-deficient in vitro under physiological concentrations. To understand the importance of the 204 residue in subdomain 4, a series of actin proteins with a single mutation at this position were created with Cys-374 retained. Only yeast expressing A204G-, A204S-, or A204C-actin were viable. The A204G and A204S strains were sensitive to cold temperature and hyperosmolarity, whereas the A204C strain showed more profound effects on growth under these conditions. Cells expressing A204C-actin exhibited anomalies previously observed for A204C/C374A actin, including abnormal actin structures. A204G- and A204S-actin proteins had 12- and 13-fold increased critical concentrations, respectively, relative to wild-type. Only at very high concentrations could A204C actin polymerize when ATP was bound; when hydrolyzed, the ADP-containing A204C filaments depolymerized, demonstrating a profound difference in critical concentration between ATP and ADP states with A204C actin. A correlation between size of the residue substituted at position 204 and energy minimization of actin filament models was observed. We propose that the region surrounding residue 204 is involved in interactions that change depending on the phosphorylation state of the bound nucleotide that might reflect different conformations of F-actin subunits.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".