| Identifier | Protein names | Gene names | Cross reference refseq | Length | Species | 
| P0CD91 | Aquaporin-1; | AQY1; AQY1-2; YPR192W; | NP_015518.1; | 305 | yeast | 
| P0CD90 | Aquaporin-like protein 2; Truncated aquaporin-2; | AQY2; AQY2-2; YLL052C; | NP_013048.1; | 149 | yeast | 
| P38115 | D-arabinose dehydrogenase [NAD(P)+] heavy chain; EC 1.1.1.117; AKR3C; | ARA1; YBR149W; | NP_009707.3; | 344 | yeast | 
| Q04212 | D-arabinose 1-dehydrogenase; EC 1.1.1.116; NAD(+)-specific D-arabinose dehydrogenase; | ARA2; YMR041C; | NP_013755.1; | 335 | yeast | 
| P40024 | ABC transporter ATP-binding protein ARB1; ATP-binding cassette protein involved in ribosome biogenesis 1; | ARB1; YER036C; | NP_010953.1; | 610 | yeast | 
| P46672 | tRNA-aminoacylation cofactor ARC1; Acyl-RNA-complex protein 1; GU4 nucleic-binding protein 1; G4p1 protein; P42; tRNA-interacting factor ARC1; | ARC1; G4P1; YGL105W; | NP_011410.1; | 376 | yeast | 
| P07347 | N-terminal acetyltransferase A complex catalytic subunit ARD1; NatA complex subunit ARD1; EC 2.3.1.88; Arrest-defective protein 1; | ARD1; YHR013C; | NP_011877.1; | 238 | yeast | 
| P25628 | Sterol O-acyltransferase 1; EC 2.3.1.26; Sterol-ester synthase 1; | ARE1; SAT2; YCR048W; | NP_009978.1; | 610 | yeast | 
| P53629 | Sterol O-acyltransferase 2; EC 2.3.1.26; Sterol-ester synthase 2; | ARE2; SAT1; YNR019W; | NP_014416.1; | 642 | yeast | 
| P11076 | ADP-ribosylation factor 1; | ARF1; YDL192W; | NP_010089.1; | 181 | yeast | 
| P19146 | ADP-ribosylation factor 2; | ARF2; YDL137W; | NP_010144.1; | 181 | yeast | 
| P40994 | ADP-ribosylation factor 3; | ARF3; YOR094W; | NP_014737.1; | 183 | yeast | 
| Q01217 | Protein ARG5,6, mitochondrial; [Cleaved into: N-acetyl-gamma-glutamyl-phosphate reductase (EC 1.2.1.38) (N-acetyl-glutamate semialdehyde dehydrogenase) (NAGSA dehydrogenase); Acetylglutamate kinase (EC 2.7.2.8) (N-acetyl-L-glutamate 5-phosphotransferase) 疩?疪 | ARG5,6; YER069W; | NP_010992.1; | 863 | yeast | 
| P18544 | Acetylornithine aminotransferase, mitochondrial; ACOAT; EC 2.6.1.11; | ARG8; YOL140W; | NP_014501.1; | 423 | yeast | 
| P00812 | Arginase; EC 3.5.3.1; | CAR1; YPL111W; | NP_015214.1; | 333 | yeast | 
| Q04728 | Arginine biosynthesis bifunctional protein ArgJ, mitochondrial; Extracellular mutant protein 40; [Cleaved into: Arginine biosynthesis bifunctional protein ArgJ alpha chain; Arginine biosynthesis bifunctional protein ArgJ beta chain] [Includes: Glutamate N疩?疪 | ARG7; ECM40; YMR062C; | NP_013778.1; | 441 | yeast | 
| P07249 | Arginine metabolism regulation protein I; Arginine-requiring protein 80; | ARG80; ARGR1; YMR042W; | NP_013756.1; | 177 | yeast | 
| P05085 | Arginine metabolism regulation protein II; Arginine-requiring protein 81; | ARG81; ARGR2; YML099C; | NP_013610.1; | 880 | yeast | 
| P53111 | NADPH-dependent aldehyde reductase ARI1; EC 1.1.1.-; | ARI1; YGL157W; | NP_011358.3; | 347 | yeast | 
| P53974 | Actin-regulating kinase 1; EC 2.7.11.1; | ARK1; YNL020C; | NP_014378.1; | 638 | yeast | 


