The phrase "altered at position" is correct and usable in written English.
It can be used in contexts where you are discussing changes made to a specific location within a sequence, such as in programming, data analysis, or genetic research.
Example: "The data was altered at position 5 to improve accuracy in the results."
Alternatives: "modified at location" or "changed at index".
In sickle cell hemoglobin, the β-globin chain is altered at position 6 by a glutamate to valine substitution (Weatherall and Provan, 2000).
In case 6, the primary tumour sequence was altered at position 9 (Supplementary Table, Supplementary Figure 2), and 19 months later, the non-neoplastic mammary gland acquired one nucleotide mutation at position 16362.
We found that the MELT-like motif is altered at position 0, −2, −2 (relative to the Thr), intermediately changing from ME[LF]T in most species to DMSLT in moths, butterflies and the beetle Dendroctonus ponderosae, MEET in mosquitos (Anophelini), and finally EP[MI]EEE in drosophilids.
Possible recombination breakpoints were identified where the most probable topology altered at different positions along the alignment.
None of the peptides altered at these positions binds any better to the MHC, nor do they stimulate any response from the cloned T cells.
(67) Charge-altering substitutions at position 195 in its P-loop altered the rate of inactivation and voltage dependence of NaChBac, whereas mutations in the N-terminal region showed no effect on inactivation rates.
The analyses of cloned HCV RNA also showed that although the nucleotide sequence spanning codons 85 87 was not altered, nucleotide changes at position 317 (CC to AT) resulted in a conformational change of the RNA structure that shifts AUG-85 from a stem into an internal loop.
With regard to the experimentally determined phenotype altering mutations at positions 7.53 and 7.60 of the rhodopsin-like 5-HT2C GPCR (19), we studied the dynamic behavior of corresponding rhodopsin mutants (Y7.53N, Y7.53F, F7.60A, Y7.53F/F7.60A, and Y7.53N/F7.60A) with essential dynamics and energy calculations to identify molecular indicators of their functional phenotypes.
The Ga mutation was identified by sequencing crtD; a single C → T base change at position 259 alters CAG to a TAG stop codon.
Genetic analysis of families revealed a putative mutation hotspot that altered an asparagine at position 102 to a serine reside [11].
The base-substitution altered amino acid at position 39 from arginine to histidine.
