Arabinose 5-phosphate isomerase KpsF kpsF MSERHLPDDQSSTIDPYLITSVRQTLAEEGARLQNLSKQLDSGQYQRVLNLIMNCKGHVILSGMGKSGHVGRKMSATLASTGTPSFFIHPAEAFHGDLGMITPYDLLILISASGETDEILKLVPSLKNFGNRIIAITNNGNSTLAKNADAVLELHMANETCPNNLAPTTSTTLTMAIGDALAIAMIRQRKFMPNDFARYHPGGSLGRRLLTRVADVMQHDVPAVQLDASFKTVIQRITSGCQGMVMVEDAEGGLAGIITDGDLRRFMEKEDSLTSATAAQMMTREPLTLPEDTMIIEAEEKMQKDKCLNVIGDQQGK Involved in the biosynthesis of K-antigen capsules. Catalyzes the reversible aldol-ketol isomerization between D- ribulose 5-phosphate (Ru5P) and D-arabinose 5-phosphate (A5P) (By similarity). Polysialic acid capsule expression protein kpsF 317 KPSF1_ECOLX K-antigen-specific arabinose 5-phosphate isomerase