Catalyzes ATP-dependent phosphorylation of adenosylcobinamide and addition of GMP to adenosylcobinamide phosphate. adenosylcob(III)inamide + GTP = adenosylcob(III)inamide phosphate + GDP + H(+) adenosylcob(III)inamide + ATP = adenosylcob(III)inamide phosphate + ADP + H(+) adenosylcob(III)inamide phosphate + GTP + H(+) = adenosylcob(III)inamide-GDP + diphosphate kcat is 15.1 min(-1) for adenosylcobinamide kinase activity. kcat is 5.6 min(-1) for guanylyltransferase activity. Optimum pH is 8.8-9.0. Optimum temperature is 37 degrees Celsius. Cofactor biosynthesis; adenosylcobalamin biosynthesis; adenosylcobalamin from cob(II)yrinate a,c-diamide: step 5/7. Cofactor biosynthesis; adenosylcobalamin biosynthesis; adenosylcobalamin from cob(II)yrinate a,c-diamide: step 6/7. Homotrimer. Belongs to the CobU/CobP family. Truncated N-terminus.