astA-I curation notes

• Q88EI3 carries the beta-chain-specific signatures IPR017650 and
  TIGR03244, supporting assignment as the beta-like component of split AstA
  [file:PSEPK/astA-I/astA-I-uniprot.txt
  "InterPro; IPR017650; Arginine_N-succinylTrfase";
  "NCBIfam; TIGR03244; arg_catab_AstA"].
• Reproducible global alignments independently support that assignment: Q88EI3
  is 85.6% identical across aligned residues to Pseudomonas aeruginosa beta
  chain P80358, versus 38.0% to alpha chain P80357
  [file:PSEPK/astA-I/astA-I-bioinformatics/RESULTS.md].
• The homologous purified Pseudomonas enzyme contains two nonidentical chain
  types and is heterotetrameric PMID:7523119. Therefore Q88EI3 contributes to, rather than independently
  enables, GO:0008791.