Non-processive alpha-1,3-D-rhamnosyltransferase (PubMed:23664878, PubMed:25845842). Catalyzes the transfer of one D-rhamnose (D-Rha) residue from donor substrate GDP-D-Rha in alpha-1-3 linkage to both GlcNAc- and GalNAc-diphosphate-lipid acceptor substrates. Is also able to transfer D-mannose (D-Man) to these acceptors at a lower level. Nucleotide sugars GDP-D-Rha, GDP-Fuc, UDP-Gal, UDP-GalNAc, UDP-GlcNAc and CMP-sialic acid cannot act as donor substrates. Only compounds with a diphosphate as the aglycone group can act as acceptor substrates. No activity is detected with compounds containing a diphosphate mimic. Fluorescent undecyl-anthracenyl group-containing compounds, such as GlcNAc-PO(3)-PO(3)-AnthrU and GalNAc-PO(3)-PO(3)-AnthrU, are also good acceptor substrates (PubMed:25845842). Involved in the biosynthesis of the common polysaccharide antigen (CPA), also called A band, which is one of the two major cell surface O-antigens of the P.aeruginosa lipopolysaccharide (PubMed:9680202, PubMed:23664878, PubMed:25845842). Involved in susceptibility to antibiotic colistin (PubMed:24474431). GDP-alpha-D-rhamnose + N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate = alpha-D-rhamnosyl-(1->3)-N-acetyl-alpha-D-glucosaminyl-1-diphospho-di-trans,octa-cis-undecaprenol + GDP + H(+) GDP-alpha-D-rhamnose + N-acetyl-alpha-D-galactosaminyl-di-trans,octa-cis-undecaprenyl diphosphate = alpha-D-rhamnosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl-1-diphospho-di-trans,octa-cis-undecaprenol + GDP + H(+) GDP-alpha-D-mannose + N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate = alpha-D-mannosyl-(1->3)-N-acetyl-alpha-D-glucosaminyl-di-trans,octa-cis-undecaprenyl diphosphate + GDP + H(+) GDP-alpha-D-mannose + N-acetyl-alpha-D-galactosaminyl-di-trans,octa-cis-undecaprenyl diphosphate = alpha-D-mannosyl-(1->3)-N-acetyl-alpha-D-galctosaminyl-1-diphospho-di-trans,octa-cis-undecaprenol + GDP + H(+) Not activated by dithiothreitol (DTT) using GlcNAc-alpha-PO(3)-PO(3)-phenylundecyl (GlcNAc-PP-PhU) as acceptor substrate (PubMed:23664878, PubMed:25845842). 0.25% Triton X-100 and 0.125% NP-40 increases the activity 2.5-fold and 2-fold, respectively. 0.125% octyl glucoside has little effect on activity. Slightly increased activity with Mg(2+) and Pb(2+), while no effect with Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Ca(2+) or EDTA. Not inhibited by N-butyryl-galactosamine-alpha-benzyl or N-butyryl-glucosamine-beta-benzyl. Bis-imidazolium salts having aliphatic spacer groups with 4 or 6 carbons have little effect on activity, but spacer groups of 18-22 aliphatic carbons inhibit activity, with the most potent inhibitor being bis-imidazolium salt having a 20-carbon chain spacer length (PubMed:25845842). Optimum pH is 9. Lipopolysaccharide biosynthesis; LPS oligosaccharide biosynthesis. Expression is up-regulated in colistin-resistant clinical isolates (GKK-1 and GKK-3) compared to colistin-susceptible clinical isolate (GKK-2). Lack of common polysaccharide antigen (CPA) biosynthesis (PubMed:9680202, PubMed:25845842). Biosynthesis of O-specific antigen (OSA), also called B band, is unaffected (PubMed:9680202). Increased susceptibility to the antibiotic colistin (PubMed:24474431). Potential target of antibacterial drug development. Belongs to the glycosyltransferase group 1 family. Glycosyltransferase 4 subfamily.