The present invention provides AAV capsid proteins (VP1, VP2 and/or VP3) comprising a modification in the amino acid sequence in the three-fold axis loop 4 and virus capsids and virus vectors comprising the modified AAV capsid protein. In particular embodiments, the modification comprises a substitution of one or more amino acids at amino acid positions 585 to 590 (inclusive) of the native AAV2 capsid protein sequence or the corresponding positions of other AAV capsid proteins. The invention also provides methods of administering the virus vectors and virus capsids of the invention to a cell or to a subject in vivo.